Answer:
A compound is a substance in which the atoms of two or more elements are chemically combined in a fixed proportion.
Explanation:
The correct answer is that a compound is a substance in which the atoms of two or more elements are chemically combined in a fixed proportion.
A compound is a substance composed of two or more kinds of atoms joined together in a definite grouping.
The properties of a compound are distinct and different from those of the individual elements that are combined in its make - up.
There are several millions of compounds known.
An element is a distinct substance that cannot be split-up into simpler substances. They are made up of only one kind of atom.
Which is not a property of an Acid?
A) low pH
B) Bitter
C) Burning Effects
D) Sour
Answer:
b bitter
Explanation: can i have brainlist please
Why do scientists need a universal system to classify organisms?
Answer:
classification enables scientists to explain the relationships between organisms, which is helpful in trying to reconstruct the evolutionary roots of a particular species. Finally, taxonomic names provide unique descriptive names for organisms. This is sometimes an issue with common names of animals.
Explanation:
Found in the Internet
How do the properties of compounds compare to the properties of elements from which they are made
Answer:
When elements combine in a chemical reaction to form compounds, their individual identity is lost. Thus, the properties of elements change when they form chemical bonds with other elements to form compounds. For example, the compound water is made up of water and hydrogen.
in the box next to your answer.
(b) Complete the sentence by putting a cross
An atom of an element always contains
D A
more protons than neutrons
B equal numbers of protons and neutrons
oc
more electrons than protons
D equal numbers of protons and electrons
Answer:
D equal numbers of protons and electrons
Explanation:
An atom of an element will always contain equal number of protons and electrons.
Atoms are electrically neutral because the number of positive charges and negative charges within them are always equal.
An atom is the smallest indivisible particles of an element that takes part in a chemical reaction. The positively charged particles within an atom are the protons. The negatively charged particles within an atom are the electrons.For;
So number of protons = number of electrons within an atom.
The number of valence electrons in sodium is/are
a 1
b 4
C2
d 3
Answer:
4
Explanation:
how many formula units are in 0.96 moles of H2O
Answer:
18.02 amu
Explanation:
which of the following gas samples would have the largest volume, if all samples are at the same temperature and pressure?
A. 0.498 moles CO2
B. 19.91 grams of Ar
C. 3 x 10^ 23 molecules of H2
D. They would all have the same volume
Answer:
C. 3 x 10^ 23 molecules of H2
Explanation:
Pls help (there is a pic)
Which of the following are considered physical changes?
[mark all correct answers]
a. Boiling water
b. Crushing a can
c. Burning wood
d. Rusting nail
e. Shredding paper
2. Why should a magnesium ribbon be cleaned before burning in air ?
Answer:
Magnesium gets covered with a layer of magnesium oxide when kept in air for a long time. This layer hinders the burning of magnesium. Hence, it is to be cleaned before burning.
Please help!!
If u know any please tell!?
Answer: 176 g N2O, 72 g H2O
Explanation:
1. 64g O2 * (1 mol O2)/(32 g O2) * (2 mol N2O)/(1 mol O2) * (44g N2O)/(1 mol N2O) = 176 g N2O
2. 32g CH4 * ( 1 mol CH4)/(16 g CH4) * (2 mol H2O)/(1 mol CH4) * (18 g H2O)/(1 mol H2O) = 72 g H2O
What causes lightning? (2 points)
a
Build up of electric charges in the clouds
b
Flow of electric charges among clouds
c
Light energy created in the clouds
d
Reflection of light by the clouds
Answer: As static charge builds up in a storm cloud, the electric field surrounding the cloud becomes ... plasma and the cloud discharges itself to the Earth through a lightning strike. ... These two mechanisms are believed to be the primary causes of the ... The contact point between ground charge and cloud charge rapidly ascends ...
Explanation:The updraft carries the super-cooled cloud droplets and very small ice crystals ... The differences in the movement of the precipitation cause collisions to occur. ... positively charged and the graupel becomes negatively charged (Figure 2). ... but important positive charge buildup near the bottom of the thunderstorm cloud due ...
Answer:
a
Explanation:
Compare the amount of current used by a 750-W microwave oven and a 1000-W microwave oven if they both operate in a 120-V circuit.
Answer:
The current used by the 750-W microwave is 0.75 times the current used by the 1,000-W microwave
Explanation:
The given parameters are;
The electrical power of one of the microwaves, P₁ = 750 W
The electrical power of the other microwave , P₂ = 1,000 W
The applied voltage of the circuit = 120-V
Electric power, P = I·V
Where;
I = The amount of current used
V = The applied voltage = 120 V
Therefore, for the first microwave, we have;
P₁ = I₁ × V
∴ I₁ = P₁/V = 750 W/(120-V) = 25/4 amperes = 6.25 amperes
The amount of current used by the 750-W microwave, I₁ = 6.25 amperes
For the second microwave, we have;
P₂ = I₂ × V
∴ I₂ = P₂/V = 1,000 W/(120-V) = 25/3 amperes = 8.[tex]\overline 3[/tex] amperes
The amount of current used by the 1,000-W microwave, I₂ = 8.[tex]\overline 3[/tex] amperes.
The ratio of the two currents, is I₂/I = (25/3 amperes)/(25/4 amperes) = 4/3
Therefore, I₂ = 4/3 × I₁, from which we have;
I₁ = 3/4·I₂
The current used by the 750-W microwave is 3/4 the current used by the 1,000-W microwave.
Some metal chips with a total volume of 3.29 cm3 are placed on a piece of paper and weighed. The combined mass is found to be 18.43 g, and the paper itself weighs 1.2140 g. Calculate the density of the metal to the proper number of significant figures.
Answer:
d = 5.23 g/cm³
Explanation:
Given data:
Volume of metal chips = 3.29 cm³
Mass of metal chips and paper = 18.43 g
Mass of paper = 1.2140 g
Density of metal = ?
Solution:
Mass of metal = combined mass - mass of paper
Mass of metal = 18.43 g - 1.2140 g
mass of metal = 17.22 g
Density:
d = mass/ volume
d = 17.22 g/ 3.29 cm³
d = 5.23 g/cm³
A photon of green light strikes an unknown metal and an electron is emitted. The voltage is set to 2 volts. The electron cannot make the journey to the second plate. What can be said about a similar experiment done with violet light? A. An electron may or may not be emitted in the second experiment. It cannot be determined. B. An electron will be emitted in the second experiment, but it cannot be determined whether it will reach the second plate. C. An electron will be emitted in the second experiment, and it will make it to the second plate. D. An electron will not be emitted in the second experiment.
Answer:
The correct answer is:
An electron will be emitted in the second experiment, but it cannot be determined whether it will reach the second plate.
Explanation:
In fact, violet has higher frequency than green light. This means that photons on violet carry more energy than photons of green light (remember that the energy of a photon is proportional to it's frequency:
[tex]e = hf[/tex]
, so when they hit the surface of the metal, more energy is transferred to the electrons. The electron was already emitted with green light, so it must be emitted with also violet light, given the more energy transferred.
When electricity passes through water (H20), the water breaks down to form
hydrogen gas (H2) and oxygen gas (02).
Which equation represents this chemical reaction?
A.2H20+ 02 – 2H2
B.2H2 + 02 – 2H20
C.2H20 + 2H2 – 02
D.2H20 - 2H2 + O2
Answer:
A. Because you have to simplify
Answer:
decomposition
Explanation:
i dont cap
The molar mass of NaCl is 58.44 g/mol. What is the molarity of a solution that
contains 120 g of NaCl in 0.750 L of solution?
0.649 M
3.00 M
2.74 M
2.05 M
How many mL are in 0.024 quarts (qt)
Answer:
99898
Explanation:
Please help quick what’s the name of the starting position of a wave in science I really need an answer fast please!
Answer:
It starts at zero, and travels to the other side. Once it reaches the other fixed point, the wave travels back to the starting poing, this is represented as the lighter line. Notice the point right in the middle at p. This point is called a node.
Explanation:
PLSS HELP! The gas carbon dioxide is a pure substance. Which of the following is true about carbon dioxide? (4 points)
a. Carbon and oxygen are chemically bonded in it.
b. Carbon and oxygen retain their original identity in it.
c. It can be separated into carbon and oxygen using physical methods.
d. The proportion of carbon and oxygen is different in different samples of the gas.
Answer:
A. Carbon and oxygen are chemically bonded in it.
Explanation:
I saw someone with the exact question and they said A so yea ♥
2. How does the particle motion of a gas affect its macroscopic behavior?
Answer: Particles in all states of matter are in constant motion and this is very rapid at room temperature. A rise in temperature increases the kinetic energy and speed of particles; it does not weaken the forces between them. ... Individual particles in liquids and gases have no fixed positions and move chaotically.
HOPE THIS HELPS
Four oranges were placed in a series circuit. Approximately what voltage did this produce?
Answer:
Four times the original amount if only one orange was used
Explanation:
We can assume that the oranges all have equal voltages. Connecting them in series will have an increasing effect on the voltage delivered. In our case, this will produce 4 times the voltage of the circuit when only one orange is used.
Whenever simple cells are connected in series, the voltages of the individual cells are added up to form the voltage of the whole circuit.
Let us assume that the voltage of each of the oranges is approximately 0.9 volts. The Voltage produced when the 4 oranges are joined in series is 0.9 + 0.9 + 0.9 + 0.9 = 3.6 volts
Describe subscripts in chemical equations.
What is the name of the piece of paper at the end of a chromatography experiment?
Answer:
There are two phases involved in chromatography; the 'stationary phase', in this case the paper, and the 'mobile phase', the salt solution. Sort the 'Smarties' into piles of the same colour.
Explanation:
(URGENT PLS HELP) Identical plants were grown in identical conditions, except one received fertilizer and water, while the other received only water.
Which best describes why the experiment either can be replicated or not replicated?
A.) The experiment can be replicated because the results were indicated.
B.) The experiment can be replicated because both plants had identical conditions.
C.) The experiment can not be replicated because no two plants are exactly the same.
D.) The experiment can not be replicated because the methods are not fully explained
Answer: It would be D, it can not be replicated becuz the methods are different. one plant had water and fertilizer, while the other only had water. You cannot replicate it you will have different outcomes because of the methods. I hope this helps you the answer is D
Explanation:
Answer:
personally I do not think that the experiment can be replicated and if it is replicated they might not get the same result.
Explanation:
It depends on how much fertilizer they used and since plants are different it might give different results. I know this isn't going to help you but go with your gut.
a student wants to determine if different types of car wheels impact how far a car will travel after leaving a ramp. The same car and the same ramp or used for each trial run. The data collected are shown in the table.
A. Large plastic Wheels
B. Large rubber Wheels
C. Small rubber Wheels
D. Small plastic Wheels
Answer:
b. it has the longest average distance
For the following reaction, how many grams of H2O will be produced if you react 2.4 grams of NH3?
4 NH3 + 5 O2 → 4 NO + 6 H2O
Answer:
ammonia is the answer
Explanation:
2.54 grams of [tex]H_{2}O[/tex] will be produced if you react 2.4 grams of [tex]NH_{3}[/tex]
The chemical reaction is given below.
[tex]4NH_{3} + 5O_{2}[/tex] → [tex]4N_{}O + 6H_{2}O[/tex]
Calculation,
Since, 17 grams of [tex]NH_{3}[/tex] produce 18 grams of [tex]H_{2}O[/tex].
2.4 grams of [tex]NH_{3}[/tex] produce 18×2.4/17 grams of [tex]H_{2}O[/tex].
So, 2.4 grams of [tex]NH_{3}[/tex] produce 2.54 grams of [tex]H_{2}O[/tex].
So, the correct option is A.
What is chemical reaction?The process in which one or more chemicals is transform into one or more chemicals is called Chemical reaction.
Example: iron and oxygen reacts with each other to form rust.
To learn more about Chemical reaction here.
https://brainly.com/question/22817140
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22. Julie took a road trip to Canada. She traveled a total of 1,750 miles in 25 hours.
Calculate Julie's average speed.
Answer:
s = 70 m/h
Explanation:
Given data:
Distance traveled = 1750 mile
Time taken = 25 hours
Average speed = ?
Solution:
Average speed can be calculated by dividing distance traveled over time taken.
Formula:
s = d/t
by putting values,
s = 1750 mile / 25 hour
s = 70 m/h
A gas occupies 50.0mL at a standard temp. What volume would it occupy at 335 Celsius with
the pressure unchanged?
Answer:
V₂ = 111.3 mL
Explanation:
Given data:
Initial volume of gas = 50.0 mL
Initial temperature = standard = 273.15 K
Final volume = ?
Final temperature = 335 °C (335+273.15 = 608.15 K)
Solution:
The given problem will be solve through the Charles Law.
According to this law, The volume of given amount of a gas is directly proportional to its temperature at constant number of moles and pressure.
Mathematical expression:
V₁/T₁ = V₂/T₂
Now we will put the values in formula.
V₁/T₁ = V₂/T₂
V₂ = V₁T₂/T₁
V₂ = 50.0 mL ×608.15 K / 273.15 k
V₂ = 30407.5 mL.K / 273.15 K
V₂ = 111.3 mL
Silicon carbide, SiC, is commonly known as carborundum. This hard substance, which is used commercially as an abrasive, is made by heating SiO2 and C to high temperatures.
SiO2(s) + 3C(s) → SiC(s) + 2CO(g)
How many grams of SiC form when 3.00 g of SiO2 and 4.50 g of C are allowed to react?
Mass of SiC = 2 g
Further explanationGiven
Reaction
SiO₂(s) + 3C(s) → SiC(s) + 2CO(g)
3.00 g of SiO₂
4.50 g of C
Required
mass of SiC
Solution
mol SiO₂ (MW=60,08 g/mol) :
= 3 g : 60.08 g/mol
= 0.0499
mol C(Ar = 12 g/mol) :
= 4.5 g : 12 g/mol
= 0.375
mol : coefficient of reactants =
SiO₂ : 0.0499/1 = 0.0499
C : 0.375/3 = 0.125
SiO₂ as a limiting reactant(smaller ratio)
Mol SiC based on mol SiO₂ = 0.0499
Mass SiC :
= mol x MW
= 0.0499 x 40,11 g/mol
= 2 g
