chemistry review

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.HS-PS1-7

A chemical reaction is balanced when

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

Tags

NGSS.MS-PS1-5

The number in front of a compound or element is a 

• Subscript
• Coefficient
• Superscript
• Charge

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

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

Tags

NGSS.HS-PS1-7

How many oxygen atoms are in this chemical formula?

• 7 oxygen atoms
• 4 oxygen atoms
• 3 oxygen atoms
• 1 oxygen atoms

Tags

NGSS.MS-PS1-1

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

Which are chemical changes

• Iron rusting 
• Glass breaking
• Clothing ripping
• Hair cut

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

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

Tags

NGSS.HS-PS1-7

In a synthesis reaction

• A compound breaks apart into two or more compounds
• Two compounds make one single product
• CO₂ and H₂O must be products
• O₂ must be a reactant

A precipitate is a 

• liquid that forms when two solids are reacted
• a solid that forms when two liquids are mixed
• a gas that forms when vinegar and baking soda react
• a change of color in a solution

Tags

NGSS.MS-PS1-2