Use the drop-down menus to answer the
questions.
Which subatomic particles are indicated by the
orange circles in the diagram?
PE
Which subatomic particles are indicated by the
green circles in the diagram?
What element is represented by the atom shown
in this diagram?

Enzymes affect the reactions in living cells by changing the

What mass of natural gas (ch4) must you burn to emit 276 kj of heat?

Observation and experimentation have led many scientists to accept a theory about the origin of the universe. this theory is called the big bang theory. scientific evidence collected and observed by scientists around the world suggests that the universe is ever expanding from a hot and dense initial state. what makes this a scientific theory? (2 points)