Atoms and molecules

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.MS-PS1-2

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

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

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

Tags

NGSS.MS-PS1-5

If a reaction starts with a total 75g of reactants it should produce 

• a total of 40g of products
• a total of 75g of products
• a total of 180 g of products
• None of the above

Tags

NGSS.MS-PS1-5

In the reaction AB-----> A + B reactant AB has 12g and product B has 5g. How many grams should product A have?

• 17g
• 2g
• 7g
• None of the above

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

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

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

The law of _____ states that mass is neither created nor destroyed during chemical reactions.

• multiple proportions

• definite proportions

• universal gravitation

• conservation of mass

Which ancient Greek philosopher was the first to propose that matter is made up of tiny individual particles called atoms?

• Proust

• Democritus

• Dalton

• Aristotle

What law states that, regardless of the amount, a compound is always composed of the same elements in the same proportion by mass?

• Law of definite proportions

• Law of conservation of mass

• Law of multiple proportions

• Law of mass action