Subatomic Particles

Which of the following is true about subatomic particles?

• The mass of a neutron is much lighter than the mass of a proton.

• Electrons are negatively charged and are the lightest subatomic particle.

• Protons are positively charged and the lightest subatomic particle.

• Neutrons have no charge and are the lightest subatomic particle.

All atoms are ____.

• positively charged, with the number of protons exceeding the number of electrons

• neutral, with the number of protons equaling the number of electrons, which is equal to the number of neutrons

• negatively charged, with the number of electrons exceeding the number of protons

• neutral, with the number of protons equaling the number of electrons

The smallest particle of an element that retains the properties of that element is a(n) ____.

• electron

• atom

• proton

• neutron

The atomic mass of an element is the ____.

• total mass of the isotopes of the element

• total number of subatomic particles in its nucleus

• weighted average of the masses of the isotopes of the element

• average of the mass number and the atomic number for the element

The particles that are found in the nucleus of an atom are ____.

• electrons only

• neutrons and electrons

• protons and electrons

• protons and neutrons

An element has an atomic number of 76. The number of protons and electrons in a neutral atom of the element are __.

• 76 protons and 76 electrons

• 38 protons and 38 electrons

• 76 protons and 0 electrons

• 152 protons and 76 electrons

The atomic number of an element is the total number of which particles in the nucleus?

• electrons

• neutrons

• protons

• protons and electrons

All atoms of the same element have the same ____.

• mass numbers

• number of protons

• mass

• number of neutrons

The sum of the protons and neutrons in an atom equals the ____.

• nucleus number

• atomic number

• atomic mass

• mass number

What does the number 84 in the name krypton-84 represent?

• the mass number

• the sum of the protons and electrons

• twice the number of protons

• the atomic number