Question

using science skills
element symbol protons neutrons electrons atomic number mass
hydrogen h 1 1
helium he 2 4
carbon c 6 6
oxygen o 8 8 16
neon ne 10 10 20
aluminum al 13 27
zinc zn 30 30 65

1. based on the table above, what is the mass number of carbon?
2. based on the table above, what is the atomic number of hydrogen?
3. based on the table above, how many electrons does an atom of aluminum contain?
4. based on the table above, an atom of which element contains two neutrons?

Explanation:

Step1: Recall mass - number formula

Mass number = Protons + Neutrons

Step2: Find protons and neutrons of carbon from table

Protons of carbon = 6, Neutrons of carbon = 6

Step3: Calculate mass number of carbon

Mass number = 6 + 6 = 12

Step4: Recall atomic - number definition

Atomic number is equal to the number of protons

Step5: Find number of protons of hydrogen from table

Protons of hydrogen = 1, so atomic number of hydrogen = 1

Step6: Recall electron - proton relationship in neutral atom

In a neutral atom, number of electrons = number of protons

Step7: Find number of protons of aluminum from table

Protons of aluminum = 13, so number of electrons of aluminum = 13

Step8: Check number of neutrons for each element

For helium, neutrons = 2

Answer:

1. 12
2. 1
3. 13
4. Helium