The Nuclear Atom

How many neutrons are in a nucleus of the nuclide?

• 17

• 20

• 37

• 54

A certain element has several isotopes. Which statement about these isotopes is correct?

• They must have different numbers of electrons orbiting their nuclei.

• They must have the same number of neutrons in their nuclei.

• They must have the same number of nucleons in their nuclei.

• They must have the same number of protons in their nuclei.

A neutral atom consists of electrons orbiting a nucleus. The nucleus contains protons and neutrons. Which statement about the atoms must be correct?

• The number of electrons is equal to the number of neutrons.

• The number of electrons is equal to the number of protons.

• The number of neutrons is equal to the number of protons.

• The number of electrons, neutrons and protons are all different.

The picture shows the symbols for five different nuclides. Which two nuclides are isotopes of the same element?

• nuclide 1 and nuclide 2

• nuclide 2 and nuclide 3

• nuclide 2 and nuclide 5

• nuclide 4 and nuclide 5

Below are four statements about isotopes of a certain element. Which statement about the isotopes must be correct?

• They are radioactive

• They are unstable

• They have the same number of neutrons

• They have the same number of protons

Which statement is correct for the nucleus of any atoms?

• The nucleus contains electrons, neutrons and protons.

• The nucleus contains the same number of protons as neutrons.

• The nucleus has a total charge of zero.

• The nucleus is very small compared with the size of the atom.

Which particles are emitted during thermionic emission?

• atoms

• electrons

• neutrons

• proton

A particular nuclide of chlorine can be represented by the symbol shown in picture. How many electrons are there in a neutral atom of this nuclide?

• 17

• 20

• 37

• 54

The diagram represents a carbon atom. What is the nucleon number (mass number) for this atom?

• 6

• 8

• 14

• 20

Helium has a mass number of 3 and atomic number of 2. Which diagram represents an atom of helium?

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