.The 1" row of the periodic table has which two elements?

Answers

Answer 1

On the periodic table, hydrogen and helium are the only two elements in the first row, or period, which reflects that they only have electrons in their first shell. Hydrogen and helium are the only two elements that have electrons exclusively in the 1 s 1s 1s orbital in their neutral, non-charged, state.


Related Questions

Question 24 of 25
How can one tell if a reaction is a redox reaction?
O A. Elements change phases.
O B. A precipitate is formed.
O C. Spectator ions are present.
O D. Electrons are gained and lost.

Answers

Answer:

D. Electrons are gained and lost

Explanation:

When electrons are gain and lost, redox reaction takes place. In redox reaction, reduction and oxidation tales place simultaneously. Therefore, option D is correct.

What is redox reaction ?

Redox reactions include a change in the oxidation state of the substrate. When electrons are lost or the oxidation state increases, it is called oxidation; when they are gained or the oxidation state decreases, it is called reduction.

Redox reactions are those in which there is a change in the oxidation number, with both an increase and a drop in number. The reaction called non-redox if this does not take place.

Oxidation and reduction always occur jointly because any loss of electrons by one substance must be followed by a gain of electrons by another. Therefore, oxidation-reduction processes or simply redox reactions are other names for electron-transfer events.

Thus, option D is correct.

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what is mass tbh pls he;p

Answers

Answer:

how much matter is in an object

Explanation:

Reactions cannot occur without a certain minimum amount of energy. What is this minimum amount of energy called?
the activation energy
the activated complex
the kinetic energy of reactants
the potential energy of products

Answers

Hello!!
It should be
“the activation energy”

The balanced equation shows how sodium chloride reacts with silver nitrate to form sodium nitrate and silver chloride. NaCl AgNO3 Right arrow. NaNO3 AgCl If 4. 00 g of NaCl react with 10. 00 g of AgNO3, what is the excess reactant? AgCl NaCl AgNO3 NaNO3.

Answers

The reactant that has been present in excess in the reaction has been NaCl. Thus, option B is correct.

The balanced chemical equation has been:

[tex]\rm NaCl\;+\;AgNO_3\;\rightarrow\;NaNO_3\;+\;3\;AgCl[/tex]

From the balanced equation, for complete utilization of 1 mole of sodium chloride, 1 mole of silver nitrate has been used.

The moles of can be given as:

[tex]\text Moles\;=\;\dfrac{m}{mwt}[/tex]

Where, mass of Silver nitrate, [tex]m=10\;\text g[/tex]

Molecular mass of silver nitrate, [tex]mwt=168\9.87\;\text {g/mol}[/tex]

Substituting the values, moles of silver nitrate has been:

[tex]\rm Moles \;AgNO_3=\dfrac{10}{169.87} \\Moles \;AgNO_3=0.058\;mol[/tex]

Mass of sodium chloride, [tex]m=4\;\text g[/tex]

Molecular mass of sodium chloride, [tex]mwt=58.44\;\text {g/mol}[/tex]

Substituting the values, moles of sodium chloride has been:

[tex]\rm Moles\;NaCl=\dfrac{4}{58.44}\\Moles\;NaCl=0.068\;mol[/tex]

From the balanced chemical equation,

[tex]\rm 1\;moles\;AgNO_3=1\;moles\;NaCl\\0.058\;mol\;AgNO_3=0.058\;mol\;NaCl[/tex]

Since, the available moles of NaCl has been 0.06 mol, and used NaCl has been 0.05 mol. Thus, NaCl has been the excess reactant.  Hence, option B is correct.

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Answer:

B- NaCl

Explanation:

if this helped could you put this as the brainiest

now imagine that you have analyzed an additional vntr. from the blot below, what is the expected frequency of occurrence?

Answers

You should re-upload this question with a picture of the plot below. Without access to that it’s impossible to answer this question.

Given the speed of light as 3.00 x 10° m/s, calculate the
wavelength of the electromagnetic radiation whose frequency
is 9.500 x 101° Hz.

Answers

Answer:

the answer is mabye 30 I didnt understand

______________ is a durable material and is widely used for casting, which is a process by which the melted material is poured into a mold. A. Bronze c. Copper b. Silver d. Gold Please select the best answer from the choices provided A B C D.

Answers

The material that has been widely used in casting has been copper. Thus, option C is correct.

Casting has been the process of molding the liquid into a specific shape with the mold. The casting involves the heating of elements and converting them into liquid. The liquid has been poured into the mold and cooling results in the casted material.

The casted material has been selected based on the boiling temperature, cooling temperature, resistivity, cost-effectiveness, and damping ability.

The material that has been consisted of these characteristics has been copper. Thus, copper has been commonly used for casting. Thus, option C is correct.

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Using the “rule of 8” explain why carbon is the backbone of organic molecules

Answers

Answer:

Carbon has 4 valence electrons (electrons that are used in bonding), and therefore it can make 4 bonds which is the most one can (other than some exceptions, but in general it is the most). It wants to make 4 bonds so it can reach a full octet of 8 elections, hence the rule of 8.

Explanation:

Answer:

I suggest you See Explanation. But tldr: Carbon forms four bonds with no lone pairs.

Explanation:

By "rule of 8" I am assuming you mean "Octet Rule." In case you don't know, the octet rule (or rule of 8) is a rule referring to the maximum number of valence shell electrons that an atom can hold: 8 electrons. However, there are exceptions to this: octet-deficient and expanded octet atoms. Octet-deficient atoms follow what is known as the duet rule (or rule of 2), as seen in the case of H and He, or have have a capacity of up to 6 electrons in their valence shell, as seen in the case of B and Be. Expanded octets contain 10, 12, or even 14 electrons and occur in Period 3 elements and after. (It was previously assumed that this was due to d-orbital hybridization but that hypothesis has been disproven and currently an explanation regarding expanded octets doesn't exist. Yet another Nobel Prize worthy concept to solve when you have free time!)

Anyways, how does this all apply to Carbon being the backbone of the millions of organic molecules? Well, carbon follows the octect rule. Unlike duet rule atoms, it is not limited to one bond with another atom. Neither does it hold many lone pairs to itself nor form over four bonds at once causing a decrease in stability. No, Carbon forms four bonds with no lone pairs and has perfect stability in terms of both formal charge and octect rule in many of its structures. Its capacity to bond to up to 4 atoms without comprimising stability is the reason why carbon is the backbone of organic molecules. If you feel this answer helped, gimme brainliest, have a great day! :)

Earth’s layers are determined by their physical properties and chemical composition. In the lesson, you learned about each of Earth’s layers, what the layers are made of, and why they are important to the Earth. In the space below, write about how the atmosphere may be classified. Would it be part of the lithosphere, or a separate layer? Explain your answer.

Answers

Answer:

The Atmosphere Is a separate layer And Also could be classified as the Closest layer

Explanation:

2) Imagine that a loudspeaker is producing quiet note with a low pitch

How will it’s viberation change

a) If the pitch of the note becomes higher?

b) If the note become louder

Answers

Answer:

Higher pitched sounds produce waves which are closer together than for lower pitched sounds. (Think of the slinky - if you produce waves rapidly they will travel quite close to each other, thus demonstrating a higher pitched sound.)

The pitch of a note will depend on a number of factors. One of these is the size of the vibrating object. On a glockenspiel or xylophone the high notes are made by the smaller bars. A smaller triangle or cymbal will make a relatively higher pitch note. On a stringed instrument such as a guitar or violin a thinner string will generally make a higher note, but also shortening the string by stopping it with the finger will produce a similar effect. On a set of pan pipes or a church organ it is the shorter pipes which make the higher notes when the air inside them vibrates.

Another factor which produces higher pitched notes is the tension within the vibrating object. A guitar string can be tuned to a higher pitch by adjusting the string tensioner. An elastic band can be stretched tighter and a drum skin can be tensioned to increase the pitch of the sound it produces.

Which of the following statement is correct regarding motors and generator?

Answers

Answer:

A. Motors and generators are opposite processes

Explanation:

B, C, and D are wrong because, the term electrical generator is used to describe a range of devices that convert mechanical energy into electricity. A motor converts electrical energy into mechanical, which is the opposite process to the electrical generator.

A scientist was in the field when he saw a mineral sample. He wanted to determine the relative hardness of the mineral, so he conducted scratch tests. He summarized his results in a table. A 2 column table with 4 rows. The first column is labeled Mineral with known hardness with entries: Chalcopyrite, pyrite, Orthoclase, Quartz. Second column is labeled Was a scratch produced? with entries: Yes, Yes, Yes, No. What conclusion can you make about the hardness of the mineral?.

Answers

The mineral hardness depends on its resistance to being scratched. Mohs scale is used to determine the hardness of an unknown mineral. The unknown mineral is harder than Orthoclase, but not harder than Quartz.

-------------------------

The hardness of a mineral is its resistance to being scratched or marked on the surface by another material.

Several elements are used to test the hardness of a mineral, like another mineral of known hardness.

Many different scales can be used to identify the mineral. However, the most commonly used is the Mohs scale.

Let us say that you have two minerals. You already know which mineral is one of them and its hardness.

If the unknown mineral scratches the known mineral, means that the first one is harder than the second one.

But if the unknown mineral does not get to scratch the known one, it means they are equally hard, or the known mineral is harder than the unknown one.

In the exposed example, the table must be as follows

    Mineral                     Was a scratch produced?              

Chalcopyrite                               YES

pyrite                                           YES

Orthoclase                                  YES                                          

Quartz                                          NO                                            

Quartz is the hardest of these minerals. Its hardness level is 7 according to the Mohs scale.

Because scratches were produced using Chalcopyrite, Pyrite, and Orthoclase, we can assume that the unknown mineral is harder than these three ones.

However, no scratch was produced using quartz, suggesting that the unknown mineral is between orthoclase and quartz in the Mohs scale.

The unknown mineral is harder than Orthoclase, but not harder than Quartz. It is between 6 and 7 hardness levels.

---------------------------

You can learn more about the Mohs scale at

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Answer:

I can conclude that the mineral that the scientist found is harder than chalcopyrite, pyrite, and orthoclase, but not harder than quartz. I can also conclude that the unknown mineral is a relatively hard mineral.

Explanation:

edge example 2023

Please help
How do we read chemical formulas?

Answers

Answer:

Download Science All formulas

Explanation:

Hope it helps

what are some negative impacts on the environment and society when the water cycle is disrupted and drought occurs ?

Answers

Some of the negative impact of disruption in water cycle are adverse environment, with affected farming, hydroelectricity, and deforestation.

The water cycle has been operated in the environment for the conversion of water in the different states. The water cycle has been operated with the conversion of water from the water body to the clouds by evaporation.

The evaporated water has resulted in clouds, that have been condensed and precipitated in the form of rain. The water cycle helps in maintaining the water balance in the ecosystem. It made the water available for use as well.

The drought has been the condition of the scarcity of water. In this condition, there has been a disruption of the water cycle. Some of the negative impacts resulting from the disruption of the water cycle are:

Adverse environmental conditionsFarming affected by water scarcityUnavailability of hydroelectricityDeforestation

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002 (part 1 of 2) 10.0 points
1.5 mol HCl and 3.7 mol NaOH react accord-
ing to the equation
HCl + NaOH → NaCl + H2O.
If the limiting reactant is HCl, calculate the
amount of NaCl formed.
1. 1.9
2. 2
3. 1.1
4. 1.5
5. 1
6. 1.8
7. 1.2
8. 1.3
9. 1.4
10. 1.7
Answer in units of mol.
mol,

Answers

Answer:

4) 1.5 mol

Explanation:

Well, the equation is already balanced and the mole to mole ratio of reactants and products are all 1. So if the limiting reactant is HCl and you have 1.5 mol, you do the mole to mole ratio with NaCl and since it is 1 to 1, there'd be 1.5 mol of NaCl.

Is a graph that starts at 25 and drops to 21, stays the same in temperature an endothermic reaction or an exothermic reaction?

Answers

Answer:

Explanation:

Endo and Exo thermic are defined by what changes take place in the environment of the reaction.

If the temperature goes up, the reaction is giving up heat. It is Exothermic.

If the temperature goes down, the reaction requires heat. It is Endothermic.

In this case, the temperature went down. The reaction is Endothermic.

How much does the universe(galaxy) weigh?

Answers

Answer:  Universe

Mass of ordinary matter

The mass of the observable universe is often quoted as 1050 tonnes or 1053 kg. In this context, mass refers to ordinary matter and includes the interstellar medium (ISM) and the intergalactic medium (IGM). However, it excludes dark matter and dark energy.

Density (of total energy): 9.9×10−27 kg/m3 ...

Mass (ordinary matter): 1.5×1053 kg

Contents: Ordinary (baryonic) matter (4.9%); D...

Volume: 3.566×1080 m3

Explanation:  Galaxy

around 1.5 trillion solar masses

Their answer: The galaxy weighs around 1.5 trillion solar masses. This number helps put in perspective how very small we are. Take, for instance, where stars in the Milky Way fit in.

Al + FeCl2 → Fe + AlCl3.

Answers

Answer:

Hope this helps :)

AlCl3 + Fe = Al + FeCl2

Chemical Equation Details aluminum chloride + iron = aluminum + iron(ii) chloride

[tex]\text{Balanced reaction:}\\\\2\text{Al} + 3\text{FeCl}_2 \longrightarrow 3\text{Fe} + 2\text{AlCl}_3[/tex]

In which of the following reactions is chlorine (Cl) oxidized? Br2 2Cl⒠→ Cl2 2Br⒠Cl2 2e⒠→ 2Cl⒠2ClO3⒠12H → Cl2 6H2O 2Na Cl2 → 2NaCl.

Answers

The reaction in which Cl has been oxidized is [tex]\rm Br_2\;+\;2\;Cl^-\;\rightarrow\;Cl_2\;+\;2\;Br^-[/tex]. Thus, option A is correct.

In a reaction, the oxidation has been defined as the loss of electrons by the atom, while reduction has been depicted as the gain of electrons.

The loss of electrons imparts a positive charge to the atom, while the gain of electrons imparts a negative charge to the atom.

In the following reactions, the Cl has been given as:

[tex]\rm Br_2\;+\;2\;Cl^-\;\rightarrow\;Cl_2\;+\;2\;Br^-[/tex]

The chlorine has loses the electron and is converted to diatomic molecule. Thus, the Cl has been oxidized. The oxidation state of Cl has also been increased from -1 to 0.

[tex]\rm Cl_2\;+\;2\;e^-\;\rightarrow\;2\;Cl^-[/tex]

The chlorine gains 2 electrons in the reaction and has been reduced.

[tex]\rm 2\;ClO_3^-\;+\;12\;H^+\;\rightarrow\;Cl_2\;+6\;H_2O[/tex]

There has been no change in the oxidation state of chlorine. Thus, Cl has not been oxidized.

[tex]\rm 2\;Na\;+\;Cl_2\;\rightarrow\;2\;NaCl[/tex]

The chlorine gains electron and has been converted to the Cl ion. With the gain of electrons, Cl has been reduced.

The reaction in which Cl has been oxidized is [tex]\rm Br_2\;+\;2\;Cl^-\;\rightarrow\;Cl_2\;+\;2\;Br^-[/tex]. Thus, option A is correct.

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helllloooook this makes no sense help me plz

Answers

may i ask?

How do you use this app?

A protozoan gains shelter as it lives in the intestine of a termites, helping the termite to be able to digest the wood that it eats. This symbiotic relationship between the termite and protozoan is known as:

Answers

Answer:

The ecological relationship between termites and the wood-digesting protozoans that live in their gut is an example of  mutualism. Thank you for posting your question here at brainly. I hope the answer will help you.

3.
What relationship do P and V have at a constant temperature? (Direct or Inverse)
1.
What relationship to V and T have at a constant pressure? (Direct or Inverse)
and please don’t put just a link thx

Answers

Answer:

3. Inverse 1. Direct

Explanation:

P- pressure

V - volume

T - temperature

P1*V1 / T1 = P2*V2 / T2 ...... (1)

That's the general gas law with the combined ideas of charles, boyle & lussac.

Whenever you are restricted as "constant" temperature, volume, or pressure...cancel them off of your equation.

in this case 3. is indirectly telling us to cancel the temperature (T).

so we'll be left w P1*V1 = P2*V2

now notice that any relation ship that is multiplied like the one above consists of inversely related quantities. & so we conclude that-

P & V are inversely proportional or have an inverse relationship.

similarly in 1. we'll cancel p off of the general formula (1)

to be left with V1/T1 = V2/T2

also note that quantities involved in division are directly related to each other & hence the answer.

10 facts about “molecules”

Answers

Answer:

Explanation:

A perfect diamond is a single molecule made of carbon atoms.

DNA is a super long molecule that has information uniquely describing every human being.

When two or more atoms chemically bond together, they form a molecule.

They are very small in size.

They have space between them.

They are in constant random motion.

molecules move when Particles move rapidly in all directions but collide with each other more frequently than in gases due to shorter distances between particles.

In 1926, French physicist Jean Perrin received the Nobel Prize in physics for proving, conclusively, the existence of molecules.

Molecules can exist in free state because they are very stable.

The smallest particle of a compound capable of existing on its own is a Molecule-not a atom.

Write out a correctly formatted hypothesis that describes how the amount of hydrogen gas produced with be affected by the concentration of acid.

Answers

When creating mixture the amount of hydrogen gas is directly related to the concentration of the acid mixture, the higher the concentration level The more hydrogen gas would be produced.

To solve such this we must know the concept of acid and base reaction. Therefore, the concentration of acid decides the concentration of hydrogen gas evolved.

What is chemical reaction?

Chemical reaction is a process in which two or more than two molecules collide in right orientation and energy to form a new chemical compound. The mass of the overall reaction should be conserved. There are so many types of chemical reaction reaction like combination reaction, double displacement reaction.

When creating mixture the amount of hydrogen gas is directly related to the concentration of the acid mixture, the higher the concentration level The more hydrogen gas would be produced.

Therefore, the concentration of acid decides the concentration of hydrogen gas evolved.

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BEBE
It is believed the major reason for the decline in amphibian species is
a. death through disease
b. changing reproductive habits
mutation
d. climate change
C.
Please select the best answer from the choices provided


Answers

Answer:

Climate change is the answer

Explanation:

They have to adapt and if the climate changes they no longer can

Answer:

climate change

Explanation:

edge 2022

1. 4Na + 02 → 2Na20
find the reaction

Answers

oxidation reaction

Explanation:

2 Na2O → 4 Na + O2

This is an oxidation-reduction (redox) reaction:

4 NaI + 4 e- → 4 Na0(reduction)

2 O-II - 4 e- → 2 O0(oxidation)

Na2O is an oxidizing agent, Na2O is a reducing agent.

Did the flower used in this investigation come from a plant that reproduces sexually or asexually? Explain your answer. (If u don’t know the answer don’t answer.) (No picture) (I didn’t know what category)

Answers

Answer:

Asexually

Explanation:

Plant's cannot reproduce sexually

Calculate the Enthalpy for the following reaction using the listed thermochemical equations:
Please help

Answers

Answer:

896.5

Explanation:

You want to manipulate each equation individually.

First Equation: Keep it how it is, because N2 is the same in the final and 1st equation

Second Equation: Multiply the enthalpy by 4 because you want the H2Os to be equal

Third Equation: Switch the sign of the enthalpy because you want toe H2O2 on the other side of the equation, and multiply by 2 to match the coefficient

Answer:

this might be of help to u

convert 150 K to degrees F

Answers

Answer:

150K is 253.67°F

Explanation:

There is a simple formula to convert from Kelvin to Celsuis;

C° = K - 273.15

    C = 150 - 273.15     C = -123.15

Then you would convert Celsuis into Fahrenheit using the formula:

[tex]F = \frac{9}{5}C + 32\\[/tex]

    [tex]F = \frac{9}{5}(-123.15)+32\\F = 221.67 + 32 \\F = 253.67[/tex]

formulas and nomenclature binary ionic compounds worksheet

Answers

To name the binary ionic compounds it is necessary to observe which is the metal and the non-metal that compose them.

This name is made as follows:

The name of the metal is shown.The name of the non-metal is presented in abbreviated form.Add the suffix "ide" at the end.

An example of this can be seen in the binary ionic composite KCL that receives the name Potassium Chloride, since potassium is the metal and chlorine is the non-metal.

It is important to remember that binary ion compounds are electrically charged ionic molecules formed by a metal and not a non-metal.

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