Why are sodium (Na) and potassium (K) in the same group on the periodic table?
1 point
They have similar atomic weights.
They are both hard and brittle.
They are both colorless.
They have similar reactivity
They have similar reactivity.
A student cuts some fabric into two pieces. Is this change physical or chemical?
1 point
It is a chemical change because the size changes.
It is a physical change because the process is reversible.
It is a chemical change because there is no phase change.
It is a physical change because there is no reaction.
It is a physical change because there is no reaction.
Which procedure could be used to demonstrate that matter is conserved during a physical change?
1 point
Find the mass of a piece of ice. Let the ice melt. Find the mass of the liquid water.
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 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.
Sodium reacts with chlorine to form the compound sodium chloride, or salt. If the total mass of the reactants is 58.44 amu, what will be the total mass of the products?
1 point
60 amu
116.88 amu
58.44 amu
29.22 amu
The total mass of the products will also be 58.44 amu.
solution is a type of:
*
1 point
pure substance
heterogenous mixture
compound
element
solution is a type of:
heterogeneous mixture
What is the pH value of a substance that is considered neutral?
*
1 point
0
7
14
10