what are the answers for Matter Interactions Unit Test unit 3 lesson 16
Matter Interactions Unit Test
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Question
What will make an atom without an electrical charge? (1 poi
Answer: An atom without an electrical charge is called a neutral atom, which means it has an equal number of protons and electrons.
What will make an atom without an electrical charge? (1 point)
Responses
More electrons than protons, because electrons are negatively charged and protons are positively charged, and electrons are much smaller than protons
More electrons than protons, because electrons are negatively charged and protons are positively charged, and electrons are much smaller than protons
An equal number of protons and electrons, because electrons are positively charged and protons are negatively charged.
An equal number of protons and electrons, because electrons are positively charged and protons are negatively charged.
An equal number of neutrons and electrons, because neutrons are positively charged and electrons are negatively charged.
An equal number of neutrons and electrons, because neutrons are positively charged and electrons are negatively charged.
An equal number of protons and electrons, because electrons are negatively charged and protons are positively charged.
An equal number of protons and electrons, because electrons are negatively charged and protons are positively charged.
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Correction:
An equal number of protons and electrons will make an atom without an electrical charge.
Thts not an answer
My apologies. The correct answer is - "An equal number of protons and electrons will make an atom without an electrical charge."
Thats not and option
My apologies for the confusion. The correct option is:
"An equal number of protons and electrons, because electrons are negatively charged and protons are positively charged."
If a substance is made of a single element, it is(1 point)\
Answer: Homogeneous, pure and an element.
If a substance is made of a single element, it is(1 point)
Responses
made of one type of atom.
made of one type of atom.
made of multiple types of atoms that have chemically bonded together.
made of multiple types of atoms that have chemically bonded together.
made through chemical reactions.
made through chemical reactions.
made of one atom.
The answer is: "Made of one type of atom."
Which element has the same number of valence electrons as bromine (Br)?
(1 point)
Responses
potassium (K)
potassium (K)
selenium (Se)
selenium (Se)
chlorine (Cl)
chlorine (Cl)
krypton (Kr
The answer is: Chlorine (Cl)
Why are sodium (Na) and potassium (K) in the same group on the periodic table?(1 point)
Responses
They are both hard and brittle.
They are both hard and brittle.
They have similar atomic weights.
They have similar atomic weights.
They have similar reactivity.
They have similar reactivity.
They are both colorless.
They are both colorless.
The answer is: "They have similar reactivity."
A student cuts some fabric into two pieces. Is this change physical or chemical?(1 point)
Responses
It is a physical change because there is no reaction.
It is a physical change because there is no reaction.
It is a physical change because the process is reversible.
It is a physical change because the process is reversible.
It is a chemical change because the size changes.
It is a chemical change because the size changes.
It is a chemical change because there is no phase change
The answer is: "It is a physical change because there is no reaction."
Matter Interactions Unit Test
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Question
Which procedure could be used to demonstrate that matter is conserved during a physical change?(1 point)
Responses
Find the mass of a raw egg. Cook the egg. Find the mass of the cooked egg.
Find the mass of a raw egg. Cook the egg. Find the mass of the cooked egg.
Find the mass of a cup of water. Boil the water. Find the mass of the water that remains.
Find the mass of a cup of water. Boil the water. Find the mass of the water that remains.
Find the mass of a piece of ice. Let the ice melt. Find the mass of the liquid water.
Find the mass of a piece of ice. Let the ice melt. Find the mass of the liquid water.
Find the mass of an apple. Cut the apple and remove the core. Find the mass of the remaining apple.
The procedure that could be used to demonstrate that matter is conserved during a physical change is:
Find the mass of a cup of water. Boil the water. Find the mass of the water that remains.
Matter Interactions Unit Test
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Question
One molecule of bromine (Br2) and two molecules of potassium chloride (KCl) combine in a reaction. How many atoms are in the products?(1 point)
Responses
six
six
four
four
two
two
three
three
The correct answer is: Four.
One molecule of Br2 contains two atoms of bromine (Br) while two molecules of KCl contain two atoms of potassium (K) and two atoms of chlorine (Cl). Thus, the products contain four atoms.
2Cu+S→Cu2S
Copper (Cu) reacts with sulfur (S) to form copper sulfide as shown in the equation. A scientist adds 12.7 grams of Cu to 3.2 grams of S to start the reaction. In this reaction, all of the copper and all of the sulfur react. Before running the experiment, the scientist expected the products of the reaction will be a total of 15.9 grams of copper sulfide (Cu2S). In 1–2 sentences, explain the law that the scientist used to predict that the product of the reaction would be 15.9 grams of copper sulfide.
(2 points)