In the graphic,
X represents which element?
31
x
15

B. X represents phosphorus

Explanation:

In an isotope symbol, you write the mass number above the atomic number. So the 31 represents the mass of the protons and neutrons of the element added together, and the 15 represents the atomic number or the total number of protons in the nucleus.

the atomic number will stay the same no matter how many electrons it has, so it doesn’t decrease nor increase. it’ll only change with a different number of protons

no, the red giant is the hottest with 2.00.000.000 degrees celsius. while the white dwarf only 25,000 degrees celsius.