Nucleus Composition and Atomic Structure in Chemistry

The video tutorial explains the concepts of atomic number and mass number. It describes how the atomic number is determined by the number of protons in the nucleus, which also equals the number of electrons in a neutral atom. The mass of the nucleus is due to both protons and neutrons, collectively known as nucleons. The mass number is the sum of protons and neutrons. An example is provided using sulfur, where the atomic number is 16 and the mass number is 32, calculated by adding the number of protons and neutrons.

What is the atomic number of an element with 11 protons?

• 11.5

• 22

• 11

• 1

In a neutral atom, the number of electrons is equal to which of the following?

• Atomic mass

• Number of protons

• Number of nucleons

• Number of neutrons

What are protons and neutrons collectively known as?

• Ions

• Electrons

• Atoms

• Nucleons

How is the mass number of an atom calculated?

• Number of neutrons plus electrons

• Number of protons plus neutrons

• Number of protons plus electrons

• Number of electrons plus nucleons

If an atom has 16 protons and 16 neutrons, what is its atomic mass?

• 32

• 16

• 64

• 48

Which element has an atomic number of 16?

• Sulfur

• Oxygen

• Nitrogen

• Carbon