8which quantity is equal to one mole of au? (1) the atomic mass in grams
(2) the atomic number in grams
(3) the mass of neutrons in grams
(4) the number of neutrons in grams

option (1) the atomic mass in grams.

Explanation:

1) The atomic mass is the mass in grams of one mole of atoms.

2) Hence, it is always the atomic mass of an element equal to the mass of one mole of atoms of such element. Therefore, the atomic mass of Au is the mass of one moles of atoms of Au.

3) Here are some examples:

i) Atomic mass of gold: 196.67 g/atoms, means that 196.97 grams of Au is one mole of Au.

ii) Atomic mass of hydrogen: 1.008 g/mol, means that 1.008 grams of H is one mole of H.

iii) Atomic mass of oxygen: 15.999 g/mol, means that 15.999 grams of O is one mole of O.

iv) Atomic mass of lead: 207.2 g/mol, means that 207.2 grams of Pb is one mole of Pb.

Now you see it, the atomic mass in grams of an element is equal to one mole of the element.

b. examine and describe cells

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.

            and  

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.