Which statement about an atom is correct?(1 point)
Responses
The electron has a negative charge and is found outside of the nucleus.
The electron has a negative charge and is found outside of the nucleus.
The neutron has no charge and is found outside of the nucleus.
The neutron has no charge and is found outside of the nucleus.
Question 2
Cobalt has a mass number of 59 and an atomic number of 27. A student wants to create a model of a cobalt atom. Which statement about the model is correct?(1 point)
Responses
The model should show 27 protons and 32 neutrons.
The model should show 27 protons and 32 neutrons.
The model should show 59 protons and 27 neutrons.
The model should show 59 protons and 27 neutrons.
Question 3
In a molecule of lithium sulfide, there are two atoms of lithium and one atom of sulfur. Which statement about lithium sulfide is correct?(1 point)
Responses
The atoms in lithium sulfide are held together by bonds.
The atoms in lithium sulfide are held together by bonds.
Both lithium and sulfur form positive ions.
Both lithium and sulfur form positive ions.
Question 4
What will make an atom without an electrical charge? (1 point)
Responses
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.
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
Question 5
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 through chemical reactions.
made through chemical reactions.
Question 6
An illustration shows the periodic table.Use the periodic table to answer the question. Which element has the same number of valence electrons as bromine (Br)?(1 point)
Responses
krypton (Kr)
krypton (Kr)
chlorine (Cl)
chlorine (Cl)
Question 7
Why are sodium (Na) and potassium (K) in the same group on the periodic table?(1 point)
Responses
They have similar reactivity.
They have similar reactivity.
They are both colorless.
They are both colorless.
Question 8
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 chemical change because the size changes.
It is a chemical change because the size changes.
Question 9
How are chemical changes different from physical changes?(1 point)
Responses
They form new substances.
They form new substances.
They are reversible.
They are reversible.
Question 10
How does a balanced chemical equation demonstrate the Law of Conservation of Mass?(1 point)
Responses
it shows that no atoms have been gained or lost during the reaction
it shows that no atoms have been gained or lost during the reaction
it shows that only physical changes follow the Law of Conservation of Mass
it shows that only physical changes follow the Law of Conservation of Mass
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Question 11
In a chemical reaction, what happens to the bonds between atoms? (1 point)
Responses
They break and new bonds form.
They break and new bonds form.
They stay the same.
They stay the same.