Biology: Molecular Basis of Life

Compound

A chemical substance composed of atoms of two or more distinct elements chemically bonded to one another.

Check the correct statements regarding a compound and a molecule:

A compound consists of two or more distinct bonded atoms, a molecule may consist of two similar elements chemically bonded, a molecule is the smallest chemical subunit of a compound

nuetron

A subatomic particle, fundamental to all matter except hydrogen, existing in the nucleus, with about the same mass as a proton, but carries no charge.

electron

A subatomic particle, fundamental to all matter, existing in orbit around the nucleus of an atom and carries a negative charge.

proton

A subatomic particle, fundamental to all matter, existing in the nucleus, with a positive charge and about equal mass to a neutron.

Molecule

A unit of matter representing the chemical properties of a substance composed of two or more atoms held together by chemical bonds.

matter

Anything which occupies space and has mass.

A molecule of one atom of carbon and two atoms of oxygen would be written:

CO2 (2 is on the bottom)

Select four of the most abundant elements found in plants and animals.

Carbon, oxygen, hydrogen, nitrogen

HCl is an example of a(n):

Compound, molecule

atomic number

The number of protons in the nucleus of the atom (Note: the number also equals the number of electrons around the nucleus).

nucleus

The positively charged center of an atom which contains both the protons and neutrons of the atom.

Which statement is correct? -electrons of a neutral atom always equals the number of protons -neutrons always equal the number of protons -atomic weight is identical to atomic mass -neutrons always equal the number of electrons

electrons of a neutral atom always equals the number of protons

In nature, on Earth, matter can exist in__________ phases.

three

There are______ elements that can be found to occur in nature.

92

Each unique element is determined by the number of________ occurring in the atom.

Protons

atomic mass

The mass of an element; approximately equal to the number of protons and neutrons in its nucleus.

atom

The smallest unit of an element that still retains the chemical properties of the element.

Each element consists of only one type of atom.

True

mixture

Two or more substances mixed together but not chemically combined.

Nitrogen gas consists of:

a molecule of two Nitrogen atoms

The smallest unit which retains the properties of an element is a(n)

atom

diatomic

containing two atoms

The common subatomic particles that make up an atom consist of protons, neutrons, and

electrons

The subatomic particles/ units which govern potential chemical reactions among elements are:

electrons

Naturally occurring compounds in the earth are called

minerals

The smallest unit of a compound is a(n)

molecule

Atomic mass is determined by the number of protons plus

neutrons

Any particular element can always be identified by its:

number of protons

Many elements exist naturally as a diatomic molecule. This means that the element is found in nature as______ chemically bonded atoms.

two