ch.2 the nature of atoms

Question 1

matter

Answer 1

any substance in the universe that has mass and occupies space is defined as matter. Matter is composed of atoms.

Question 2

Atomic number

Answer 2

= the number of protons in an atom.

Question 3

atomic mass

Answer 3

equal to the sum of the masses of its protons and neutrons.

Question 4

daltons

Answer 4

=the mass of atoms and subatomic particles is measured in units called daltons.
ex. 602 million million billion daltons to make 1 gram

Question 5

Electrons: charge, location, and purpose/neutral atoms

Answer 5

-positive charges in the nucleus are neutralized by negatively charged electrons, which are located in regions called orbitals.
-atoms w/ the same # of protons and electrons are electrically neutral; no net charge; called neutral atoms

Question 6

Ions and cations and anions):
when do you get them and what are they?

Answer 6

Ions = atoms where the number of electrons does not equal the number of protons are ions.

Cation = An atom having more protons than electrons has a positive charge and is called a cation. (negatively charged with fewer protons is called anion).

Question 7

Isotopes

Answer 7

-when atoms of an element don’t have the same number of neutrons. Atoms that have different numbers of neutrons are called isotopes of that element.

Question 8

orbitals

Answer 8

spherical s
hourglass-shaped p

Question 9

oxidation and reduction

Answer 9

during some chemical reactions, electrons are transferred from one atom to another. In these reactions, the loss of an electron is called oxidation and the gain is called reduction.

Question 10

redox reactions

Answer 10

when the process of oxidation and reduction are coupled– one atom/molecule is oxidized while another is reduced. these combinations are redox reactions.