* 20 POINTS

A ________ is made of two or more elements chemically combined.


a.

alloy


b.

mixture


c.

element


d.

compound

Answers

Answer 1

Answer:

Compound is the answer


Related Questions

Methylene Chloride (MC) is a common ingredient of paint removers. Besides being an irritant, it also may be absorbed through skin. When using this paint remover chemical protective clothing should be worn. If thick butyl rubber gloves (0.1 cm thick) are used, D in butyl rubber is 110 x 10-8 cm2/s, and surface concentrations are 0.44, and 0.02 g/cm3. If the surface of a glove is 50 cm2, the amount of MC transported through the glove in 3 hours will be: Answer in grams (g).

Answers

Answer:

2.5 g

Explanation:

First we have to calculate the diffusion flux (J). To calculate, we use the formula:

[tex]J=-D\frac{dC}{dx}=-D\frac{C_2-C_1}{x_2-x_1}\\ \\Given\ that:\\\\x_2-x_1=0.1\ cm,D=110*10^{-8}cm^2/s,C_2=0.02g/cm^3,C_1=0.44g/cm^3\\\\Substituting:\\\\J=-110*10^{-8}(\frac{0.02-0.44}{0.1} )=4.62*10^{-6}g/cm^2s\\\\But, J=\frac{M}{At}\\ \\t=3\ hours=10800\ s,A=50\ cm^2\\\\Substituting:\\\\4.62*10^{-6}=\frac{M}{50*10800}\\ \\M=4.62*10^{-6}*50*10800\\\\M=2.5\ g[/tex]

For the equation 2KCI + CaF₂ ⇒ 2 KF + CaCI₂, 55.1 mol KCI is reacted with 46.7 mol CaF₂.

1. What is the limiting reactant?

2. How many moles of KF will be produced?

Please Show all your work!! Thank you!

Answers

Answer:

Explanation:

Finding Limiting reactant:

Convert all reactant data to moles, divide by respective coefficient => smaller value is the limiting reactant.

Given      2KCl      +     CaF₂ => 2KF + CaCl₂

            55.1mole      46.7mole

(55.1/2) = 27.55          (46.7/1) = 46.7

Limiting reactant is KCl b/c smaller value after dividing by respective coefficients. CaF₂ will be in excess when rxn consumes all KCl.

Moles KF = 55.1 mole as coefficients of two substances in balanced equation are equal.

Answer:

2

Explanation:

Which characteristic of life is described as the transfer of DNA from parent to offspring, and is important for keeping a species alive

A. Homeostasis


B. Cell Organization


C. Heredity

Answers

Answer:

C. Heredity

Explanation:

Homeostasis means that an organism can control its own body temperature. This is important because if we couldn't control our temperature, then our cells would have trouble working properly from being to hot or cold.

Cell organization means that our body and cells can organize themselves into groups that work together. For example, cells form groups and tissue for different organs while other cells form nerves.

Heredity is the passing of genes from parent to offspring

16. As he developed his periodic table, Mendeleev grouped the elements lithium,
sodium, and potassium together. What observation was likely a factor in his decision
to group these elements?

Answers

Answer:

the reactivity and the valence electrons

Explanation:

the reactivity of the elements would have played a significant role in why such elements were grouped together. the number of valence electrons dictates how reactive an element is - the less valence electrons the more reactive it is. the column, group 1 in which these elements are put together in, show that each of the elements have 1 valence electrons and are therefore reactive.

you can go on to further explain what valence electrons are, explain what the group numbers are associated with the valence electrons and how valence electrons effect reactivity. further this, talk about how the three elements have the same number of valence electrons and therefore were grouped together

The reactants are

A

the substances present when the reactions begin.


B

the substances present when the reaction is complete.


C

the properties that change after the reaction.


D

the energy that is released or stored during the reaction.

pls, hurry!!!!!!!!!!!!!!!!

Answers

It’s c because I took the test

Which example is a trace fossil?


dinosaur footprint


wooly mammoth tusk


insect in amber


dinosaur egges characteristics of a mineral

Answers

Answer:

dinosaur footprint

Explanation:

dinosaur footprint because the deffinition of trace fossil is a fossil of a foot print

Answer: Dinosaur footprint should be correct!

Explanation: As in the name, trace footprints are practically just traces, so a Dino print is a perfect example! The dinosaur left a trace, leaving evidence about it, for science to study:) please let me know if this helps! :)

The isotope of an atom containing 31 protons and 39 neutrons suddenly has two neutrons added to it. What isotope is create?

Answers

The answer is gallium-72

1. Lani conducted an experiment in which she tested the reactivity of a substance. She placed two
equal samples of a substance into identical beakers. She then filled one beaker with water and
filled the other with vinegar. After a week, she measured the samples. What was the
independent variable in her experiment?

Answers

Answer:

the independent variable is the beakers

Explanation:

The gas inside a neón light compone or element

Answers

Answer:

element

Explanation:

the gas inside a noble gas is made of only one neon atom and is less reactive and would not likely combine with any other element

Compare and contrast ionic and covalent bonds by explaining what the electrons do when bonding occurs. Use details to support your answer.WILL GIVE BRAINLIEST

Answers

DescriptionIonic bonding is a type of chemical bonding that involves the electrostatic attraction between oppositely charged ions, or between two atoms with sharply different electronegativities, and is the primary interaction occurring in ionic compounds,


A covalent bond, also called a molecular bond, is a chemical bond that involves the sharing of electron pairs between atoms. ... For many molecules, the sharing of electrons allows each atom to attain the equivalent of a full outer shell, corresponding to a stable electronic configuration.

Which of the following is least like the others on the list?

a. Amino acid
b. Ribonucleic acid
c. Nucleic acid
d. Nucleotides

Answers

Explanation:

C option i think but I didn't know

Select the true statement(s) abut Polymers: Group of answer choices Thermoplastics have low melting temperature because of the week van der Waals bonds between their Long Chain Molecules Thermoplastics have low strength because of the week van der Waals bonds between their Long Chain Molecules Polymers have low densities because of the week van der Waals bonds between their Long Chain Molecules Polymer chains once synthesized they will remain stable in the environment because of the strong covalent bonds in the Long Chain Molecules

Answers

Answer:

Thermoplastics have low melting temperature because of the week van der Waals bonds between their Long Chain Molecules

Polymer chains once synthesized they will remain stable in the environment because of the strong covalent bonds in the Long Chain Molecules

Explanation:

Thermoplastics are polymers that are easily melted and changed to another shape as many times as possible. They become molten when they are heated and solidify when cooled. Examples of thermoplastics include; polyethylene, polypropylene, polyvinyl chloride, polystyrene, polyamides, polyesters, and polyurethanes.

Polymers are organic materials that consists of a long chain of atoms held together by strong covalent bonds. Polymers constitute an important environmental concern because most polymers are non biodegradable and remain in the environment almost indefinitely.

the pH of a HClO4 solution was measured as 4.251. What would be the concentration of HClO4 in this solution

Answers

Answer:

[tex]0.000056[/tex]

Explanation:

If [tex]pH[/tex] is given then hydronium ion concentration is equal to [tex]-log[H_3O^+][/tex]

The hydronium ion concentration can be found from the pH using the following formula:

Hydronium ion concentration = [tex]10^{-pH}[/tex]

As the pH of a HClO4 solution was measured as 4.251,

put [tex]pH=4.251[/tex]

So,

Concentration of HClO4 in the solution = [tex]10^{-4.251}=0.000056[/tex]

Complete the equation for the conversion of sucrose into glucose
(1)C12H22O11 + H2O

Answers

Answer:

C₁₂H₂₂O₁₁ + H₂O     →    C₅H₁₂O₆ + C₆H₁₂O₆

Explanation:

Chemical equation:

C₁₂H₂₂O₁₁ + H₂O     →    C₅H₁₂O₆ + C₆H₁₂O₆

Source of sucrose:

Sucrose is present in roots of plants and also in fruits. It is storage form of energy. Some insects and bacteria use sucrose as main food. Best example is honeybee which collect sucrose and convert it into honey.

Monomers of sucrose and hydrolysis:

Sucrose consist of monomers glucose and fructose which are join together through glycosidic bond. Hydrolysis break the sucrose molecule into glucose and fructose. In hydrolysis glycosidic bond is break which convert the sucrose into glucose and fructose. Hydrolysis is slow process but this reaction is catalyze by enzyme. The enzyme invertase catalyze this reaction.

The given reaction also completely follow the law of conservation of mass. There are equal number of atoms of elements on both side of chemical equation thus mass remain conserved.

Which atom has the greatest ionization energy?
C
N
O
F

Answers

Answer:

helium

The ionization energy decreases from top to bottom in groups, and increases from left to right across a period. Thus, helium has the largest first ionization energy, while francium has one of the lowest.

helium. the energy decreases from top to bottom & increases left to right

what do borates do structurally that none of the other non silicates with anionic complexes do g

Answers

Answer:

Kindly check the explanation section.

Explanation:

The chemical compound known as Borates has the Molecular Formula: BO3^-3. It has the shape of a triangle but Borates can form multiples ones that is to say quadrangles. Also, as a result of the fact that the octect is not complete, Borates are used as lewis Acid.

The oxygen present in Borates is/are directly attached to the central atom that is Boron while in non silicates the oxygen(s) that may be present is not directly attached to the central atom.

Explain the difference between the reactants and
products of a chemical reaction.
MP

Answers

Answer:

HOPE THIS HELPED :) good luck! ❤️

Explanation:

A reactant is a substance that is present at the start of a chemical reaction. The substance to the right of the arrow are called products . A product is a substance that is present at the end of a chemical reaction.

Answer:

Reactants are the starting substances and products are the ending substances in a chemical reaction.  The atoms in reactants are arranged one way and are rearranged in a different way to form the products (in other words, reactants are chemically different from products). The properties of reactants differ from the properties of products.

Explanation:

Sample response on Edge 2021

what are the names of the subatomic particles in an atom

Answers

Answer:

Protons, Neutrons and electrons

Explanation:

I have a question. Does anyone have a crush on their classmates? I do!

Answers

Answer:

I never had a crush on anyone

Explanation:

It is expected that as the temperature goes up by the above method, frozen carbon dioxide will defrost and evaporate into the atmosphere, raising temperatures even more. Why would this be

Answers

Answer:

CO2 is a green house gas

Explanation:

CO2 is believed to act as a canopy over the earth's surface absorbing infrared (heat ray) from the earth and re-emitting it  back to the earth.

By so doing, temperature is increased and more frozen CO2 will defrost causing even greater temperature rise.

The gradual rise in the earth's temperature is known as global warming.

All living things are made of organic compounds which contain the element
A)
carbon.
B)
hydrogen.
C)
oxygen.
D)
phosphorus.

Answers

c
explanation; ( i’m smart )

Which characteristics describe the genetic code of humans? Select three options

Answers

Answer:

1.  Can help in development of effective medications

2.  Can help explain genetic diseases

3.  Composed of about 19,000 genes

Explanation:

The other answer options are misleading.

Genetic code of humans can help with understanding more than just human genetics.

Human genetics is composed of 23 chromosome pairs, for a total of 46 chromosomes.

what are proteins? (simple definition please)

Answers

Proteins are large biomolecules, or macromolecules, consisting of one or more long chains of amino acid residues. Hope this helps!

Answer:

Proteins are carbohydrates that come from nutritious food.

They are one of the four main carbohydrates.

This is a simple definition of the word proteins.

Hope this helps!

Explain the arrangement of the first 20 elements in the periodic table.
Please help! Will give brainliest!

Answers

Elements are arranged from left to right and top to bottom in order of increasing atomic number.

There are various kind of elements that are present in periodic table. Elements that are metals are kept on left side of periodic table and elements which are non metals are kept on right side of periodic table.

What is periodic table?

Periodic table is a table in which we find elements with properties like metals, non metals and metalloids element arranges in increasing atomic number.

The first 20 elements of periodic table are Hydrogen, Helium, Lithium, Beryllium, Boron, Carbon, Nitrogen, Oxygen, Fluorine, Neon, Sodium, Magnesium, Aluminum, Silicon, Phosphorus, Sulfur, Chlorine, Argon, Potassium and Calcium. Out of these Lithium, Beryllium, Sodium, Magnesium. Potassium and Calcium are metals so they are kept on the left side of the periodic table while others are non metals so they are kept on right side of periodic table.

Learn more about periodic table, here:

https://brainly.com/question/11155928

#SPJ2

What is the air temperature 8,850 m in the air?

Answers

The temperature is gonna be

2. What is the pH of the following solutions?
2.1. 50 mmol.dm solution of Ba(OH)2

Answers


i hope this helps (please mark brainliest)

how many protons electrons and nuetrons does zn have​

Answers

Zn has 30 protons and electrons and 35 neutrons.

4. How many joules of heat energy does it take to burn off 500 000 cal of potato chips?
(1 cal = 4.184 )) Show your work.​

Answers

Answer:

[tex]2,092,000J[/tex]

Explanation:

Hello.

In this case, we need to perform a unit conversion problem between cal and joule, taking into account that 1 cal equals 4.184 joules of energy, therefore, we write the following proportional factor:

[tex]500,000cal*\frac{4.184J}{1cal}[/tex]

Whereas the 1 cal is written under the line in order to simplify the initial can and the 4.184 J on the line as joules are the required units. Thus, we obtain:

[tex]2,092,000J[/tex]

As the energy required to burn off such amount of energy given of potato chips.

Best regards.


"Why does a hamburger have fewer calories than a steak? Because it's in the ground state!" Explain the joke while also highlighting what the ground state means for electrons in a way that someone who has never taken chemistry before will understand.

Answers

Answer:

it means a hamburger has less calories bc its referring to steak that has been grounded and the highlight would be calories

A crate is pulled with a force of 165 N at an angle 30 °
northwest. What is the resultant horizontal force on the crate?
Help asap

Answers

Answer:

143 N

Explanation:

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