law of conservation of mass

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-PS1-5

NGSS.MS-PS1-2

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

The number in front of a compound or element is a 

• Subscript
• Coefficient
• Superscript
• Charge

The number to the lower side of an element is a 

• Subscript
• Superscript
• Coefficient
• Charge

Tags

NGSS.MS-PS1-1

Which is Chemical Equation is Balanced?

• CH₄+O₂------CO₂+2H₂O
• H₂+O₂-----2H₂O₄
• 4Al+3O₂-----2Al₂O₃

Tags

NGSS.MS-PS1-5

How many nitrogen atoms does NH₃ have?

• 1
• 2
• 3
• 4

Tags

NGSS.MS-PS1-1

Is this equation balanced or unbalanced? 
2Fe₂O₃ + 3C --> 4Fe + 3 CO₂

• balanced
• unbalanced

Tags

NGSS.MS-PS1-5

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

24 g of magnesium reacts with 38 g of fluorine to produce _____ g magnesium fluoride

• 62 
• 38
• 24
• 14

Tags

NGSS.MS-PS1-5

NGSS.MS-PS1-2

What is the law of conservation of mass?

• The amount of matter changes when reacted or changed.
• The mass of all reactants are changed during a physical or chemical change
• The mass of the reactants equals the mass of the products
• The mass of the products is different than the mass of the reactants.

Tags

NGSS.MS-PS1-5