Unit 2 - Atomic Theory

H Chemistry

Subatomic particles are the particles inside where?

An atom of an element

What are the 3 subatomic particles?

electrons, protons, neutrons

Charge, location & mass of Neutrons:

neutral, in nucleus, 1amu

Charge, location & mass of Protons:

positive(+), in nucleus, 1amu

Charge, location & mass of Electrons:

negative(-), outside the nucleus (in “cloud”), negligible

What is the same number of protons and electrons in an atom?

The atomic number

What is the same number of protons and neutrons in an atom?

The atomic mass

What are isotopes?

Atoms of the same element that have a different number of neutrons

What effect does an isotope have on an element’s mass?

The mass numbers are different

How do we represent isotopes in symbolic form?

Nuclear notation

In nuclear notation, what does X, A, and Z represent?

X=element symbol, A=mass number, Z=atomic number

When writing out isotopes we write it like _______.

“Element-mass number” (ex: carbon-13)

What are ions?

Atoms of the same element with a different number of electrons

Ions can be _____?

Charged (positive or negative)

What change to the number of electrons will produce a negatively charged ion?

Extra electrons

What change to the number of electrons will produce a positively charged ion?

Missing electrons

What is a negatively charged ion called?

Anion

What is a positively charged ion called?

Cation

The atomic mass of an atom is the _______ mass of an atom of an element.

average

The ______ accounts for the amount of isotopes of that element and how often they appear in nature.

atomic mass

What is relative abundance?

The percentage of that particular isotope that exists in nature

Isotopes don’t exist with the ______ abundance as other isotopes.

Same

Most elements are made up of a _____ of isotopes.

mixture

The sum of the percentages of the specific isotopes must add up to?

100%

What is the formula for relative abundance?

(Isotope Mass Number * Relative Abundance) + (Isotope Mass Number * Relative Abundance) = Average Atomic Mass

What is electron configuration?

A “code” to show how many electrons are in an atom and where they are

What is around an atom?

Energy levels

The farther an energy level is from the nucleus, the _____ energy the sublevel has.

more

What does each energy level have that is represented by “n”?

A principal quantum number

When n=1, it means _____?

Energy level 1

What do orbitals of probability show?

The most likely position of each electron

Orbitals of probability are found in ______?

Each energy level

What are sublevels?

Orbitals of probability within an energy level

What has different shapes and can hold different numbers of electrons?

Sublevels

What letters are sublevels represented by?

s, p, d, and f

When n=1, there is only 1 sublevel:

s

When n=2, there are 2 sublevels:

s & p

When n=3, there are 3 sublevels:

s, p, & d

When n=4, there are 4 sublevels:

s, p, d, & f

How many electrons can the s sublevel hold?

2 (1 pair)

How many electrons can the p sublevel hold?

6 (3 pairs)

How many electrons can the d sublevel hold?

10 (5 pairs)

How many electrons can the f sublevel hold?

14 (7 pairs)

The s block starts at what energy level?

1

The p block starts at what energy level?

2

The d block starts at what energy level?

3

The f block starts at what energy level?

4

The exponents add up to the total number of _______ in that atom

electrons

Electrons fill the ______ energy level before moving up

lowest

In an orbital diagram, what do the arrows represent?

Electrons

What has a certain number of orbitals with electrons in them?

Sublevels (s,p, d, f)

What is noble gas configuration?

A form that consists of the element symbol of the last noble gas prior to that atom, followed by the configuration of the remaining electrons

Why can we do the noble gas shortcut?

Because they have their electron shells filled up

True or false: when doing relative abundance we state our answer using sig figs

false! We don’t use sig figs