What is the inner and most dense layer of the sun

The core is the inner and most dense layer of the sun, it's hotter than the sun itself!

Explanation:

d: the voltage of the secondary coil is less than that of the primary coil.

im not suree sorry if wrong

explanation:

let the different atoms be x and y. each with four protons and same mass will be represented as follows.

mass number is number of protons + number of neutrons.

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since, it is given that one has a negative charge while the other is neutral. therefore, there will be increase in number of protons and the atom will be represented as follows.

according to periodic table, mass number of beryllium is 9 and it has atomic number 4 so, the atoms will be and .  

the protons and neutrons will be located inside the nucleus whereas the electrons will be revolving around the nucleus.