Ch 2: The Chemistry of Biology

If an element has a mass number of 35 and an atomic number of 17, how many neutrons are present in the atom?

18

If an element has an atomic number of 19 and its mass number is 39, the number of neutrons must be__________.

Blank 1: 20 or twenty

Each element has unique characteristics, for example, nitrogen has an atomic number of___________ and oxygen has an atomic number of __________.

Blank 1: 7 or seven Blank 2: 8 or eight

The organization of ____________ begins with individual building blocks called atoms.

Blank 1: matter

An electron ____________ is a specific volume of 3-dimensional space in which an electron is likely to be found.

Blank 1: orbital

Atomic _____________ is the measurement of the gravitational pull on the mass of a particle, atom, or object.

Blank 1: weight

An energy shell is where which of the following occurs?

Electrons are found in pairs.

True or false: Protons found in a hydrogen atom are different in structure from protons found in an oxygen atom.

False

True or false: The mass number of an element is based on the total number of electrons and protons found in each atom.

False

Which of the following is anything that has mass and occupies space?

Matter

Isotopes are variant forms of the same element that differ in the number of which of the following?

Neutrons

Which of the following structures differ in hydrogen and oxygen atoms?

Number of subatomic particles

Electrons can be found in pathways surrounding the center of the atom; these pathways are known as which of the following?

Orbitals

The atomic number of an element represents the number of which subatomic particles in the nucleus?

Protons

The mass number of an element is the sum of the number of which two of the following?

Protons Neutrons

Which of the following does not change in an element?

The number of protons

The atomic ________ of an element is the average mass numbers of all isotopic forms.

mass