Question

What can you say about a calcium atom by looking at the symbol 44/20 Ca?
a. A calcium atom has 44 neutron s and 20 electrons.
b. A calcium atom has 20 protons and 24 electrons.
c. A calcium atom has 64 protons and 20 neutrons.
d. A calcium atom has 20 protons and 24 neutrons.
e. A calcium atom has 20 protons and 44 neutrons.

Answer 1

The answer is d. a calcium atom has 20 protons and 24 neutrons. The 20 means the atomic number. The 44 means the atom mass which is the total of neutrons and protons. 

Answer 2

the symbol for Ca is

⁴⁴₂₀Ca

the subscript 20 is the atomic number. Atomic number is the number of protons in the atom. Atomic number is characteristic for the element

this means that Ca atomic number is 20 and it has 20 protons

the superscript 44 is mass number/ atomic mass. The mass of the atom is a sum of neutrons and protons.

neutrons + protons = 44

since protons = 20

neutrons = 44 - 20 = 24

number of protons - 20 and neutrons = 24

the correct answer is d. A calcium atom has 20 protons and 24 neutrons.