Calculate the average atomic mass of an element that has an isotope with a mass of 11.00 amu (60% abundance) and another isotope with a mass of 10.53 (40% abundance). What is this element? Make sure to prove this with your math calculations.

Helium

He

atomic number 2.

It is a colorless, odorless, tasteless, non-toxic, inert, monatomic gas,

Explanation:

These different types of helium atoms have different masses (3 or 4 atomic mass units ), and they are called isotopes. For any given isotope, the sum of the numbers of protons and neutrons in the nucleus is called the mass number. This is because each proton and each neutron weigh one atomic mass unit (amu). By adding together the number of protons and neutrons and multiplying by 1 amu, you can calculate the mass of the atom. All elements exist as a collection of isotopes. The word ‘isotope’ comes from the Greek ‘isos’ (meaning ‘same’) and ‘topes’ (meaning ‘place’) because the elements can occupy the same place on the periodic table while being different in subatomic construction.

the answer is c. nacl