Grade 8 Q2 Review Quiz

What is one of the characteristics of chemical change?

• There is a change in the shape of the substance.

• A new substance is formed.

• No new substance is formed.

• Mostly are reversible changes.

These are the observations that we can make to see the chemical changes, except...

• Size change

• Color change

• Bubbles formed

• light formed

When 23 grams of sodium react with 32 grams of oxygen, how many grams of sodium oxide is produced?

• 65 grams

• 55 grams

• 45 grams

• 35 grams

The ratio by mass of carbon and oxygen is 3:8 in the compound carbon dioxide. If 6 grams of carbon used to produce carbon dioxide, how many grams of oxygen is needed?

• 24 grams

• 16 grams

• 8 grams

• 4 grams

What is the chemical formulae of this compound?

• $PCl_3$

• $NH_3$

• $BF_3$

• $CCl_4$

What do we do to change the ice to become water?

• Decrease its temperature

• Increase its temperature

• Stabilize its temperature

• Put the ice in the refrigerator

These are the main properties of non-metals, except...

• Low melting points

• Brittle

• Shiny

• Insulators

What do we do to store the alkali metals?

• Store the metals with water

• Store the metals with oil

• Store the metals with oxygen

• Store the metals with acid

From the list of elements in group 1, which element is the most reactive?

• Magnesium

• Potassium

• Sodium

• Lithium

The reaction between sulfuric acid with sodium oxide will produce?

• Sulfuric oxide

• Sodium oxide

• sodium acid

• potassium oxide