Which change is chemical?(1 point) water undergoing electrolysis
water boiling
water evaporating
water freezing

Which number remains unchanged during photosynthesis?(1 point)

the number of glucose molecules
the number of carbon dioxide molecules
the number of carbon atoms
the number of water molecules

In a chemical reaction, which aspect of the reactants changes?(1 point)

atoms
total mass
mass
nuclei
A young snake eats and digests a mouse. The increase in the snake’s mass equals(1 point)

the mass of the mouse minus the mass of waste produced by the snake.
the mass of the mouse plus the mass of waste produced by the snake.
the mass of the mouse.
the mass of the mouse plus the original mass of the snake.
Cellular respiration transforms glucose and oxygen into carbon dioxide, water, and energy.

C6H12O6 + 6O2 → 6CO2 + ?H2O + Energy

Based on the law of conservation of matter, what is the missing coefficient for water?

(1 point)

2
4
6
8