Because an atom is neutral, the number of A
electrons equal the number of protons.
B
protons equal the number of neutrons.
isotopes equal the number of neutrons.
D
electrons equal the number of neutrons.

Explanation:

An atom is nuetral when the number of protons is equal to the number of electrons.

Electrons and protons have the same but opposite charge which is 1.6 × 10^-19.

So since they have the same charge they need an equal number of protons and electrons in the atom for it to be nuetral.

So it is A

answer: 802.3 kilo joules of energy represents 191.75 kilo calorie of energy.

explanation:

energy released during combustion of one mole methane = 802.3 kilo joules

if 1 kilo joule = 0.239006   kilo calorie

then ,802.3 kilo joule will be = 802.30.239006 kilo calorie

802.3 kilo joule = 191.75 kilo calorie

hence, the energy in kilo calorie is 191.75 kilo calorie.

the bal will not change its velocity.