Physical Science Chapter 15

What is a nucleon?

A nucleon is a subatomic particle of the atomic nucleus. This includes the proton and the neutron.

What happens to the properties of elements across any period of the periodic table?

Across any period, the properties of elements gradually change.

What is the atomic symbol for the element cobalt?

As can be found in the periodic table, the atomic symbol for the element cobalt is Co.

Distinguish between atomic number and mass number.

Atomic number is the number of protons in the nucleus. Mass number is the total number of protons and neutrons in the nucleus.

What was the source of motion in the particles that Brown investigated?

Atoms bumping into the particles.

What role does atomic number play in the periodic table?

Elements are listed in the periodic table in order of increasing atomic number.

Which atom is most plentiful in the universe?

Hydrogen

Distinguish between mass number and atomic mass.

Mass number is the count of nucleons in an isotope. Atomic mass is a measure of the total mass of an atom.

Is it possible to see an atom using visible light?

No. Atoms are smaller than the wavelengths of visible light and so cannot be seen using any visible light microscope.

Distinguish between a proton and a neutron in terms of electric charge.

Proton has one unit of charge, neutron has none.

Why is pure gold classified as an element?

Pure gold consists of only one type of atom, which is the gold atom.

How many shells are needed to explain the periodic table?

Seven.

What is at the center of every atom?

The atomic nucleus.

Which electrons are most responsible for the properties of an atom?

The electrons in the outer most shell of an atom, called the valence electrons, are the ones most responsible for the properties of an atom.

What is the relationship between the maximum number of electrons each shell can hold and the number of elements in each period of the periodic table?

The number of electrons that each shell can hold corresponds to the number of elements in the period.

How many groups are there in the periodic table?

The periodic table has 18 groups.

How many periods are there in the periodic table?

The periodic table has 7 periods.

What type of microscope allows us to visualize the positions of individual atoms?

The scanning probe microscope.

How many nucleons are there in Hyrogen-3?

Three.

What occurs for two atoms to be isotopes of each other?

Two atoms are isotopes of each other when they have the same number of protons but a different number of neutrons.