Unit Test — Unit test Answers

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4

How many atoms of each element are in the chemical formula NH4NO3?

A
1 nitrogen, 1 hydrogen, and 3 oxygen
B
1 nitrogen, 4 hydrogen, and 3 oxygen
C
2 nitrogen, 4 hydrogen, and 3 oxygen
D
5 nitrogen, 1 hydrogen, and 1 oxygen
6

How do the nuclei of covalently bonded atoms help keep the bond together?

A
Neutral particles in the nucleus provide enough mass that the force of gravity holds the atoms together.
B
Neutral particles in the nucleus can become positive or negative in order to balance the charges.
C
Positive particles in the nucleus change into negative particles that enter electron shells.
D
Positive particles in the nucleus are attracted to shared electrons, so the atoms stay close together.
7

By which process does water vapor become a cloud?

A
evaporation
B
transpiration
C
condensation
D
precipitation
8

Suna passes an electric current through a sample of clear, colorless, and odorless liquid. As the experiment continues, bubbles form, and the volume of liquid decreases. Suna collects samples of two colorless, odorless gases that bubble out of the liquid. One of the gases burns. Neither the original liquid nor the other gas burns.Which is the best explanation of her results?

A
The electric current changed some of the sample to gas even though the sample was not breaking down. Therefore, the original liquid is a compound.
B
The electric current released a gas that was odorless and colorless, like the original sample. Therefore, the original liquid is an element.
C
The sample was broken down by the electric current and formed a new substance that could burn. Therefore, the original liquid is a compound.
D
The sample lost some of its volume, but the gas still had the same chemical makeup as the original sample. Therefore, the original liquid is an element.
9

Formaldehyde is an organic compound. Each molecule includes two hydrogen (H) atoms, one oxygen (O) atom, and one carbon (C) atom. Below are the dot structures for each of these elements.Which diagram shows how the covalent bonds most likely form in a formaldehyde molecule?

Question illustration
A
Option
B
Option
C
Option
D
Option
10

What is a limitation of using a chemical formula, such as C6H12O6, to represent a compound?

T
The chemical formula does not show the types of elements that make up the compound.
T
The chemical formula does not show how the atoms are connected to one another.
T
The chemical formula does not show the number of atoms of each element in a molecule.
T
The chemical formula does not show the chemical symbols of the elements in the compound.
11

What would happen to life on Earth if all the liquid fresh water were used up?

A
All organisms would adapt to using salt water.
B
Organisms would carry out life functions without water.
C
Animals would be affected, but some desert plants would survive.
D
Life could no longer exist on Earth.
12

Which term best describes all atoms in ionic bonds?

A
stable
B
unstable
C
positively charged
D
negatively charged
13

Giovanni created this chart to study for an exam.Which best describes how to correct the error in the chart?

Question illustration
A
Remove “plastics” from the uses for sodium hydroxide.
B
Swap the uses for iron oxide and calcium carbonate.
C
Change the use for calcium chloride to “used in preservatives.”
D
Add “de-ice roads” to uses for calcium carbonate.
14

What does the chemical formula C3H6O2 tell about a molecule of the compound it represents?

A
It is made up of 3 atoms of 11 different elements.
B
It is made up of 11 atoms joined in a straight line.
C
It is made up of 11 total atoms of 3 different elements.
D
It is made up of 1 atom composed of 3 different elements.
15

What causes an ionic bond to form between sodium and chlorine?

A
Sodium and chlorine atoms share electrons.
B
Sodium and chlorine atoms switch electrons.
C
Sodium atoms gain electrons.
D
Sodium atoms donate electrons.

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