Law of mass conservation

The number to the lower side of an element is a 

• Subscript
• Superscript
• Coefficient
• Charge

The number in front of a compound or element is a 

• Subscript
• Coefficient
• Superscript
• Charge

Which of these is not a chemical reaction?

• Burning of wood
• Milk going bad
• Mixing vinegar and baking soda
• Melting of ice

The coefficient in  3H₂O is

• 6
• 2
• 3
• 5

If reaction starts with 20g of reactants it should produce 

• a total of 40g of products
• a total of 10g of products
• a total of 80 g of products
• a total of 20g of products

In a reaction A + B ----> C,  reactant A has 5g and product  C has 9g. How many grams does reactant B should have? 

• 4g
• 5g
• 9g
• 14g

What is the Law of Conservation of mass?

• Mass is created in a chemical reaction
• Mass is created in a physical change
• New chemicals formed from a chemical reaction have a larger overall mass than the original reactants
• Mass is never created or destroyed

Which are the reactants in the following reaction?
2Mg + O₂ ---> 2MgO 

• Mg and O
• MgO
• Mg and MgO
• O and MgO

When sodium and chlorine combine to form sodium chloride, sodium chloride is the:

• Originator

• Reactant

• Product

• Produce

Maria fills a bowl with 200 g of water. She puts the bowl of water in the freezer, and the water freezes. Which will most likely be the mass of the frozen water?

• 50 g
• 100 g
• 200 g
• 400 g