A student cuts some fabric into two pieces. Is this change physical or chemical?(1 point)
Responses
It is a physical change because the process is reversible.
It is a physical change because the process is reversible.
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 there is no phase change.
It is a chemical change because there is no phase change.
It is a chemical change because the size changes.
It is a physical change because there is no reaction.
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.
They involve heat.
They involve heat.
They include shifts in the phase of matter.
They form new substances.
How does a balanced chemical equation demonstrate the Law of Conservation of Mass?(1 point)
Responses
it shows that the properties of the elements stay the same after the reaction
it shows that the properties of the elements stay the same after 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
it shows that all compounds remain bonded after the reaction
it shows that all compounds remain bonded after the reaction
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 no atoms have been gained or lost during the reaction.
Use the chemical reaction to answer the question.
2H2+O2→□ H2O
Which number will balance the equation?
(1 point)
Responses
4
4
6
6
2
2
8
4
Sodium reacts with chlorine to form the compound sodium chloride, or salt. The chemical formula below shows how the two elements combine into a compound.
2Na + Cl2 → 2NaCl
If the total mass of the reactants is 58.44 amu, what will be the total mass of the products?
(1 point)
Responses
116.88 amu
116.88 amu
29.22 amu
29.22 amu
58.44 amu
58.44 amu
60 amu
60 amu
The total mass of the products will also be 58.44 amu.
Which procedure could be used to demonstrate that matter is conserved during a physical change?(1 point)
Responses
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 an apple. Cut the apple and remove the core. Find the mass of the remaining apple.
Find the mass of an apple. Cut the apple and remove the core. Find the mass of the remaining apple.
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 a raw egg. Cook the egg. Find the mass of the cooked egg.