unit #2

matter

__________ is any substance that has mass and has volume (takes up space).

elements

Substances that cannot be broken down into simpler substances by chemical reactions are known as __________.

atom

The smallest unit of an element that retains the properties of that element is a(n) __________.

protons

The subatomic particle that has a positive charge is the

neutrons

The subatomic particle that has a neutral (zero) charge is the

electrons

The subatomic particle that has a negative charge is the

nucleus

Most of the mass (>99.94%) of an atom is in its __________.

protons & neutrons

The nucleus contains the atom's

electrons

The nucleus is orbited by the atom’s __________, which have negligible mass.

atomic

An atom's proton count is referred to as the __________ number.

isotopes

Atoms of the same element (same atomic number), but different neutron counts are referred to as __________.

orbitals

Electrons inhabit “probability clouds” called __________.

valence

The group of orbitals farthest from the nucleus is referred to as the __________ shell.

periodic table

In 1869, a Russian chemist named Dmitri Mendeleev developed a way of arranging the elements in a table by increasing atomic mass. This table is called the __________ of Elements

molecules

__________ are groups of two or more atoms bonded together with atomic bonds.

ionic & covalent

There are two types of chemical bonds -

ionic

__________ bonds involve an exchange of electrons between two or more atoms.

ion

When an atom gains or loses electrons, it becomes a(n) __________.

covalent

__________ bonds involve the sharing of electrons between two or more atoms.

polar or non-polar

Covalent bonds may be ______ or ______, depending on whether electrons are shared unequally or equally.

non-polar

________ covalent bond, electrons are shared equally.

polar

_______ bond, electrons are shared unequally.

solvent & solute

A solution always contains two parts:

acid

any substance that donates a hydrogen ion (H+).

base

any substance that can accept a hydrogen ion (H+).

acidic

1-<7 is considered

neutral

7 is considered

basic

>7-14 is considered

carbon

Organic chemistry is the chemistry of the element __________.

polymer

A(n) __________ is a large molecule (macromolecule) composed of repeating subunits.

monomer

A single subunit of a polymer is called a __________.

carbohydrates

__________ are polymers of monosaccharides, or simple sugars. 

hydrophobic

Lipids are described as being __________, or "water-fearing".

amino acids

Proteins are polymers of __________  __________.

nucleic acids

__________  __________ are polymers of nucleotides. 

DNA & RNA

The two types of nucleic acids are