New substances produced by a chemical reaction are _______.

• resultants
• reactants
• coefficients
• products

The law of conservation of mass states that _______.

• matter can be created and destroyed but does not change forms
• in a chemical reaction, efforts should be made to preserve rare elements without changing them
• in a chemical reaction, matter is not created or destroyed, but is conserved
• in a chemical reaction, the final mass of the products is always greater than the starting mass of the reactants

What are valence electrons?

• sum of the protons and neutrons
• protons minus electrons
• electrons in the inner shells
• electrons in the outer shell

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2

If an atom has 7 protons and 7 electrons what charge will it have?

• -2
• -1
• 0
• +2

Tags

NGSS.MS-PS1-1

How many valence electrons does oxygen have?

• 2
• 4
• 5
• 6

Tags

NGSS.HS-PS1-1

An electron has what kind of charge?

• positive
• negative
• neutral
• none of these

How many atoms of carbon (C) are in C₆H₁₂O₆?

• 3
• 6
• 12
• 24

Tags

NGSS.MS-PS1-1

Element or compound?
H₂O

• element
• compound

Tags

NGSS.MS-PS1-1

Which of the following is a compound?

• Co
• O₂
• C
• CO₂

Tags

NGSS.MS-PS1-1

The blue numbers in the image below represent ________

• I don't know, and don't want to try
• coefficients
• subscripts
• none of the answers are correct

Tags

NGSS.MS-PS1-1