AnswersLHS Physical ScienceUnit Test

Unit Test — Cumulative exam Answers

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Which tools would Sara use to find an irregularly shaped object’s mass and volume?

A
a meter stick, a ruler, and water
B
a meter stick, a balance, and water
C
a balance, water, and a ruler
D
a balance, water, and a beaker
2
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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.
3

Which is the property of nonmetals to evaporate easily?

A
brittle
B
dense
C
liquid
D
volatile
4

An atomic physicist determines that an atom is composed of 8 positively charged particles and has a mass of 15 amu. Which is the best conclusion that can be drawn?

A
The atom has 7 neutrons and 8 protons.
B
The atom has 7 electrons and 8 protons.
C
The atom has 8 neutrons and 7 electrons.
D
The atom has 8 electrons and 7 protons.
5

When balanced, which equation would have the coefficient 3 in front of any of the reactants?

A
Zn + HCl ZnCl2 + H2
Option A
B
H2SO4 + B(OH)3 B2(SO4)3 + H2O
Option B
C
Fe + AgNO3 Fe(NO3)2 + Ag
Option C
D
C2H4O2 + O2 CO2 +H2O
Option D
6

Which metal is most likely to form more than one kind of positively charged ion?

A
sodium (Na)
B
barium (Ba)
C
nickel (Ni)
D
magnesium (Mg)
7

Which element is most likely to carry electric current easily?

A
tin (Sn)
B
sulfur (S)
C
antimony (Sb)
D
selenium (Se)
8

In the reaction C + O2 → CO2, 18 g of carbon react with oxygen to produce 72 g of carbon dioxide. What mass of oxygen would be needed in the reaction?

A
18 g
B
54 g
C
72 g
D
90 g
9

These models show the electron structures of two different nonmetal elements.

Question illustration
A
Element 1 is more reactive because it has fewer electron shells and is toward the top of its group on the periodic table.
B
Element 1 is more reactive because it has more electrons in its valence shell and is farther to the right on the periodic table.
C
Element 2 is more reactive because it does not have a valence shell close to the nucleus, so it will attract electrons.
D
Element 2 is more reactive because it does not have a full valence shell, so it will attract electrons.
10

The diagram shows organisms a diver observed during an ocean dive.

Question illustration
A
the ocean surface
B
the ocean floor
C
the position of the clownfish
D
the position of the seaweed
11

Marco wants to investigate the chemical properties of sodium bicarbonate, or baking soda. He plans to carry out the tests below.Test 1: Mix a teaspoon of sodium bicarbonate into a cup of warm water to see if it dissolves.Test 2: Mix a teaspoon of sodium bicarbonate into a cup of vinegar to see if it fizzes.Test 3: Heat a teaspoon of sodium bicarbonate in the oven to see if its melting point is less than 400 degrees Fahrenheit.

O
Only Test 3 will indicate a chemical property of sodium bicarbonate. Tests 1 and 2 will show a physical property of the substance.
O
Only tests 1 and 2 will indicate chemical properties of sodium bicarbonate. Test 3 will show a physical property of the substance.
O
Only Test 2 will indicate a chemical property of sodium bicarbonate. Tests 1 and 3 will show a physical property of the substance.
O
Only tests 1 and 3 will indicate chemical properties of sodium bicarbonate. Test 2 will show a physical property of the substance.
12

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.
13

What is an atomic nucleus?

A
the outer part of an atom in which electrons move
B
the outer part of an atom in which neutrons move
C
the central part of an atom, composed of protons and neutrons
D
the central part of an atom, composed of protons and electrons
14

The model below shows an atom of an element.

Question illustration
6
6
8
8
9
9
1
16
15

Atoms of arsenic (As) are often added to silicon (Si) in a process called doping to change the conductivity of the silicon. How does the addition of arsenic change the conductivity of silicon?

A
An atom of arsenic has one fewer valence electron and more electron shells than an atom of silicon, so the conductivity decreases because the arsenic atom gains an electron.
B
An atom of arsenic has one more valence electron and more electron shells than an atom of silicon, so the conductivity decreases because the arsenic atom loses the electron.
C
An atom of arsenic has one fewer valence electron and fewer electron shells than an atom of silicon, so the conductivity increases because the arsenic atom gains an electron.
D
An atom of arsenic has one more valence electron and more electron shells than an atom of silicon, so the conductivity increases because the arsenic atom loses the electron.
16

[BLANK]

A
synthesis
B
polymerization
C
decomposition
D
oxidation
E
replacement
17

Particle A has very little mass in comparison to Particle B. Both particles are in the same atom. Which is the best conclusion about Particles A and B?

A
They have the same charge.
B
They are located in the nucleus together.
C
Particle A has a positive charge, and Particle B is neutral.
D
Particle A orbits the nucleus, and Particle B is located in the nucleus.
18

Scientists have changed the model of the atom as they have gathered new evidence. One of the atomic models is shown below.

Question illustration
A
A few of the positive particles aimed at a gold foil seemed to bounce back off of the thin metallic foil.
B
Experiments with water vapor showed that elements combine in specific proportions.
C
Equations were used to identify regions around the nucleus where electrons would likely be.
D
Cathode rays were bent in the same way whenever a magnet was brought near them.
19

Sonya is studying a nonmetal element. She learns that the element is like other elements in its group because it can bond to form a salt or an acid. She also learns that the element is the most reactive element in its group. Which element is Sonya most likely studying?

A
sulfur (S)
B
neon (Ne)
C
fluorine (F)
D
iodine (I)
20

What are the coefficients for the reaction _Cl2O5 + _H2O → _HClO3 once it is balanced?

A
1, 1, 1
B
1, 1, 2
C
1, 2, 2
D
2, 1, 1

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