Answer: By definition, if the atomic number =
7
, then there are 7 protons, 7 electrons, and 8 neutrons!
Explanation:
The atomic number is by definition the number of protons, positively charged particles, contained within the atomic nucleus. So if there are 7 protons, there MUST be 7 electrons, 7 negatively charged particles. Why? Because matter is electrically neutral, and positive and negative particles must be equal.
Electrons have negligible mass; the mass number depends on the number of protons contained within the nucleus, PLUS the number of neutrons. Given that we have 15 N
, there must be 8 neutrons contained within the nucleus. does this help?
Answer:
Rectus Femoris
Explanation:
It has an action of extending the knee from a seated position.
I hope this helps, and as always, I am joyous to assist anyone at any time.
The answer is Permian-Triassic extinction.
The Permian-Triassic extinction was 252 million years ago. It is known as The Great Dying because about 95% of all species died out due to environmental changes (volcanic eruptions, dry climate, melting of ice sheets, etc). This is also the only event in which many insect species wiped out.
The possibility to answer is C.
