Conservation of Mass & Counting Atoms

What is the atomic number of this atom?

• 4
• 5
• 9
• none of the above

What is the mass number of this atom?

• 4
• 5
• 9
• none of the above

What is the mass number?

• the number of protons
• the number of protons and neutrons
• the number of neutrons
• the number of protons and electrons

Matter can not be created nor destroyed: it can only be

• Destroyed a little bit
• Invisible
• Transformed, changed
• None of the above

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

A chemical reaction is balanced when

• both sides have the same elements
• Both sides have the same  number of atoms
• Same subscripts
• Same coefficients

Which of these is not a chemical reaction?

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

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

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

• Originator

• Reactant

• Product

• Produce