Law of Conservation of Mass Test

The small number to the lower side of an element is a 

• Subscript
• Superscript
• Coefficient
• Charge

A chemical reaction is balanced when

• both sides have the same elements
• Both sides have the same  number of atoms of each element

• Same subscripts
• Same coefficients

Tags

NGSS.MS-PS1-5

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

Tags

NGSS.MS-PS1-5

NGSS.MS-PS1-2

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

Tags

NGSS.MS-PS1-5

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

Tags

NGSS.MS-PS1-5

What will weigh more when a chemical change is complete?  The reactants before the chemical reaction, or the product after the reaction is complete?

• They both will weigh the same
• The product always weighs more than the reactant
• The reactant will weigh more than the product
• They both will loose mass after the reaction

Tags

NGSS.MS-PS1-5

NGSS.MS-PS1-2

Since gasses weigh nothing, when they are produced in a reaction they do not have to be accounted for.  

• True
• False

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

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

How many oxygen atoms are in this chemical formula?

• 6 oxygen atoms
• 2 oxygen atoms
• 3 oxygen atoms
• 4 oxygen atoms

Tags

NGSS.MS-PS1-1