Hello!
The atomic number is determined only by the number of protons in the nucleus of an atom. But, in a neutral atom it also represents the number of electrons in the electron cloud.
Neutrons are only important in the nucleus for helping us find atomic weight, which varies as we move along the perodic table and does not always equal the same amount of it's atomic number. Which is why it would not be a suitable answer for the first blank space. Electrons do not work either as they do not exist inside the nucleus but rather outside the atom.
The second space, since it states is in the electron cloud, we can deduct that electrons would be an appropriate answer there.
If you need anymore help feel free to ask, but I hope this answers your question.
Gravity pulls gas and dust together. A protostar forms as mass increases.
Explanation:
Many meteorites have iron or nickel in them, so they are heavier (and denser) than Earth rocks. Some meteorites have pits (regmaglypts) on the outside, which look like deep thumbprints. Meteorites are not bubbly, and do not have holes. Meteorite are usually not round.
One kilogram is the answer