CHEM Test 1 (12th) 21-22

What is the atomic number?

• The number of protons in the nucleus of an atom

• The number of neutrons in the nucleus of an atom

• The number of protons and neutrons in the nucleus of an atom

What is the mass number?

• The total number of neutrons in a nucleus.

• The total number of protons and neutrons in a nucleus.

• The total number of electrons in a nucleus.

What is an isotope?

• Forms of the same element that contain equal numbers of neutrons but different numbers of protons in their nuclei

• Forms of the same element that contain equal numbers of protons but different numbers of neutrons in their nuclei

• None of the above

What is an isobar?

• Each of two or more isotopes of different elements, with the same atomic weight.

• Each of two or more isotopes of different elements, with different atomic weight.

• None of the above

It is assumed that electrons behave as particles.

• Bohr's Atomic Model

• Schrödinger's Atomic Model

The majority of the atom's size is just empty space, also called vaccum.

• Bohr's Atomic Model

• Schrödinger's Atomic Model

We can predict the position of an electron by using Newtonian Mechanics.

• Bohr's Atomic Model

• Schrödinger's Atomic Model

Electrons behave not only as particles but also as waves.

• Bohr's Atomic Model

• Schrödinger's Atomic Model

Since electrons behave also as waves, Newtonian Mechanics became obsolete therefore:

• Classical Mechanics was developed

• Quatum Mechanics was developed

Heisenberg proposed that:

• it is possible to find simultaneously the position and momentum of an electron

• it is not possible to find simultaneously the position and momentum of an electron