Counting Protons, Neutrons, & Electrons

What is the atomic number of an element?

• The atomic number of an element is the number of neutrons in the nucleus of an atom.

• The atomic number of an element is the number of protons in the nucleus of an atom.

• The atomic number of an element is the number of electrons in the nucleus of an atom.

• The atomic number of an element is the number of protons and neutrons in the nucleus of an atom.

Answer explanation

The atomic number of an element is a fundamental property that defines the element. It represents the number of protons in the nucleus of an atom. This number is unique for each element and determines its position in the periodic table. The other options, such as the number of neutrons, electrons, or the combination of protons and neutrons, do not define the atomic number.

What is the mass number of an element?

• Total number of neutrons in the nucleus

• Total number of protons in the nucleus

• Total number of electrons in the nucleus

• Total number of protons and neutrons in the nucleus

Answer explanation

The mass number of an element is the total number of protons and neutrons in the nucleus. This is because the mass of an atom is primarily determined by the number of protons and neutrons it has. Electrons contribute very little to the overall mass. Therefore, the correct answer is 'Total number of protons and neutrons in the nucleus'.

How do you count the number of protons in an atom?

• By counting the number of neutrons in the atom

• By looking at the atomic number of the element

• By looking at the atomic mass of the element

• By observing the color of the atom

Answer explanation

The number of protons in an atom can be determined by looking at the atomic number of the element. The atomic number represents the number of protons present in the nucleus of an atom. Other options, such as counting neutrons, observing the color, or looking at the atomic mass, do not provide information about the number of protons.

How do you count the number of neutrons in an atom?

• Divide the atomic number by the mass number.

• Add the atomic number to the mass number.

• Multiply the atomic number by the mass number.

• Subtract the atomic number from the mass number.

Answer explanation

To count the number of neutrons in an atom, you need to subtract the atomic number from the mass number. The atomic number represents the number of protons, while the mass number is the sum of protons and neutrons. By subtracting the atomic number, you isolate the number of neutrons in the atom.

How do you count the number of electrons in a neutral atom?

• Mass number

• Proton number

• Valence number

• Atomic number

What is the atomic number of an atom with 6 protons?

• 2

• 4

• 8

• 6

How many protons are there in a calcium atom?

• 20

• 30

• 10

• 40

How many neutrons are there in an Fe atom with mass number 56?

• 40

• 30

• 50

• 25

How many electrons are there in a neutral atom of oxygen?

• 6

• 10

• 12

• 8

Tags

NGSS.MS-PS1-1

What is the atomic number of an atom with 8 protons?

• 2

• 4

• 8

• 6