He is using an arthroscope. Which is use to examine a joint.
Answer:
Ca has 20 protons, so neutral it would have 20 electrons, but according to the charge, 2 electrons have been lost.
Explanation:
Gravity , Explosion
<u>Explanation:</u>
Nebulae are made of dust and gases—mostly hydrogen and helium. The dust and gases in a nebula are very spread out, but gravity can slowly begin to pull together clumps of dust and gas. As these clumps get bigger and bigger, their gravity gets stronger and stronger.
Eventually, the clump of dust and gas gets so big that it collapses from its own gravity. The collapse causes the material at the center of the cloud to heat up-and this hot core is the beginning of a star.
A. they divide in two
i dont know b sorry
