14 practice sets · Page 1 of 1
Which of the following is an example of an element that exists as isotopes?
Hydrogen
Oxygen
Carbon
All of the mentioned
Correct Answer: D — All of the mentioned
Explanation:
Hydrogen, oxygen, and carbon all have isotopes with different numbers of neutrons.
What is the principal cause of the atomic spectra produced by elements?
Electrons jumping from lower to higher energy levels
Protons emitting radiation
Electrons moving in circular orbits
Electrons changing position within an orbital
Correct Answer: A — Electrons jumping from lower to higher energy levels
Explanation:
Atomic spectra are produced when electrons transition between energy levels.
What is the maximum number of electrons in the third shell of an atom?
32
8
18
2
Correct Answer: C — 18
Explanation:
The third shell can hold a maximum of 18 electrons.
What is the charge of an atom that has 10 protons, 10 electrons, and 12 neutrons?
Positive
Negative
Neutral
Undefined
Correct Answer: C — Neutral
Explanation:
An atom with equal numbers of protons and electrons is electrically neutral.
What is the atomic mass unit (amu) based on?
Mass of carbon-12 isotope
Mass of a proton
Mass of a neutron
Mass of an electron
Correct Answer: A — Mass of carbon-12 isotope
Explanation:
One atomic mass unit is defined as one-twelfth the mass of a carbon-12 atom.
The electron configuration of sodium (Na) is 2, 8, 1. What is the number of electrons in the outermost shell of sodium?
10
2
1
8
Correct Answer: C — 1
Explanation:
Sodium has one electron in its outermost shell.
Which of the following particles are found in the nucleus of an atom?
Only neutrons
Electrons and neutrons
Protons and neutrons
Electrons and protons
Correct Answer: C — Protons and neutrons
Explanation:
The nucleus contains protons and neutrons.
What is an atom?
The smallest particle of an element
A particle of a compound
A type of molecule
A part of a molecule
Correct Answer: A — The smallest particle of an element
Explanation:
An atom is the smallest particle of an element that retains its chemical properties.
The discovery of the neutron was made by?
Niels Bohr
James Chadwick
Ernest Rutherford
J.J. Thomson
Correct Answer: B — James Chadwick
Explanation:
James Chadwick discovered the neutron in 1932.
Which part of the atom contains the protons and neutrons?
Nucleus
Electron cloud
Shells
Orbitals
Correct Answer: A — Nucleus
Explanation:
Protons and neutrons are located in the nucleus of an atom.
What is the atomic number of an element with 6 protons and 6 electrons?
12
6
4
8
Correct Answer: B — 6
Explanation:
Atomic number is equal to the number of protons in an atom.
Which of the following elements has an atomic number of 6?
Hydrogen
Carbon
Nitrogen
Oxygen
Correct Answer: B — Carbon
Explanation:
Carbon has an atomic number of 6.
What is the smallest particle of an element?
Proton
Molecule
Ion
Atom
Correct Answer: D — Atom
Explanation:
An atom is the smallest unit of an element that retains its properties.
Which subatomic particle has a negative charge?
Neutron
Electron
Proton
Both proton and electron
Correct Answer: B — Electron
Explanation:
Electrons carry a negative charge.
