Chemistry

Chemistry With Shoenberger! Midterm units 1-3

Chapters:

1.1 - Particle Nature of matter

1.2 - Modeling Atoms

1.3 - Atomic Emission Spectra

1.4 - Modern Atomic theory

1.5 - Electrons in atoms

Unit 1: Atomic Structure

1.1 - Particle Nature of matter

Chemistry

Meaning: Branch of science that investigates/ explains the structure and properties of matter

Matter

Meaning: Anything that has massand takes up space

What is matter?

• The heat and light from a lamp (energy)

• Thoughts and ideas

• Radio waves

• Magnetic fields

Atoms and elements

Atoms - The building block of matter

Elements - The simplest form of matter, made of only one type of atom

Ex: Bismith Bi, Gallium Ga

• Name, symbol 1-2

Molecules

Meaning: 2 or more atoms chemically combined held together by chemical bonds

Molecules have a chemical formula

• What atom + How many make up a molecule

Chemical bonds

Meaning: A strong force of attraction that holds two atoms together

Chemical formula

Meaning: Shows how many atoms of each element make up one molecule of the substance

• Solid: very strong, fixed pattern, and molecules vibrate

• Liquid: less Strong, and molecules move freely

• Gas: Move far apart

The motion of particals determine the state of matter

Total Kinetic Energy of all particles that make up matter

​Thermal Energy:

Motion

Kinetic Energy:

Energy:

Energy stored in chemical bonds

​chemical Energy:

Stored energy due to postion

Potental Energy:

Energy:

Multiple Choice

Which of the following is true about liquids?

• They have more motion / kinetic energy than a gas

• They have stronger attractive forces than solids

• They have weaker attractive forces than gases

• They have definite volume but not a fixed shape

Multiple Choice

True or false: The attractive forces between particles of a solid is so strong that there is absolutely no molecular motion that occurs

• True

• False

Multiple Choice

True or false: Chemistry is a branch of science that investigates and explains the structure and properties of matter

• True

• False

Multiple Choice

Which type of energy is stored in the chemical bond atoms of a substance?

• Thermal Energy

• Kinetic Energy

• Chemical Energy

• Light Energy

Multiple Choice

A measure of the total kinetic energy of all the particles that make up matter is…?

• Thermal Energy

• Kinetic Energy

• Chemical Energy

• Light Energy

Multiple Choice

Which of the following is true about the composition of an atom?

• Electrons account for the majority of the Atom's mass

• The nucleus accounts for the majority of the atom's volume

• Atoms are mostly empty space with a small dense central nucleus

• Atoms are negatively charged particles of matter

1.2 - Modeling Atoms

Atoms are made of:

• Protons- positively charged

• Neutrons- no charge

• Electrons- negatively charged

All matter is made of atoms

Atomic composition

​	​Protons:	​Neutrons:	​Electrons
​Symple form	​P	N	​e
​Charge	​+1	0​	-1​
​Mass	​1 amu	​1 amu	​Does not count towards atomic mass

The number of protons determines an atom's identity and physical/chemical properties

Isotopes

Atoms that have the same number of protons but different numbers of neutrons

Average atomic mass

Weighted average mass of all naturally occurring isotopes of an element

Avg atomic mass = (isotope 1 mass × % abundance) + 2

Multiple Choice

Which of the following represents a chemical formula for a compound?

• Hydrogen - 3

• 24He

• H₂O

• All of these represent a chemical formula

Multiple Choice

The image shows a model of a copper atom. How many electrons are in this copper atom?

• 32

• 27

• 29

• 19

Multiple Choice

How many neutrons are there in...

• 88

• 138

• 226

• 314

Multiple Choice

Which of the following represents a pair of isotopes?

• Calcium-40 and potassium-40

• Hydrogen-1 and Hydrogen-2

• Water and Oxygen

• ₇N and ₈O

Multiple Choice

An atom of an element with the atomic number 35 and the mass number of 80 contains:

• 35 protons, 35 electrons, and 80 neutrons

• 80 protons, 35 electrons, and 35 neutrons

• 35 protons, 35 electrons, and 45 neutrons

• 45 protons, 35 electrons, and 80 neutrons

Multiple Choice

An isotope of sodium (atomic #11) is found to have 13 neutrons. Therefore, its mass number must be:

• 13

• 23

• 24

• Not enough information provided to determine this

1.3 - Atomic Emission Spectra

Atomic emission spectra

Meaning: pattern formed when light emitted by an element is separated into the different wavelengths it contains

Ex: A fingerprint for elements - each has its own unique emission spectra

Ground state: The electron is in its lowest possible energy level

​​Excited state:

The electron has gained energy and is in a higher energy level

Return to the ground

​When an element absorbs energy in a gaseous state, its electrons become excited and the atom becomes unstable.

Energy levels

Meaning: Fixed energy levels an electron can have

Quantum

Meaning: The amount of energy required to move an electron from one energy level to another

Electrons in the Bohr model follow the same number of elements in a row on the periodic table

• Level 1- 2 electrons

• Level 2- 8 electrons

• Level 3- 8 electrons

• Level 4- 18 electrons

• Level 5 - 18 electrons

• Level 6- 32 electrons

• Level 7- 32 electrons

Draw

Draw the bohr model for Neon!

Use blue for the electrons!

1.4 - Modern Atomic Theory

Quantum Model

Quantum mechanical model

Meaning: The modern description of electrons in atoms

Atomic orbital

Meaning: Region of space where there is a high probability of finding an electron

Shells

Main energy level of electrons (1 - 7)

Shell 1: Closest to the nucleus - lowest energy

Shell 7: Farthest from the nucleus - highest energy

Subshells

Meaning: Divitions within shells

S - Sphere = 1 orbital (2 e-), P - Peanut = 3 orbital (6 e-), D - clovery = 5 orbital (10 e-), F - Flowery = 7 orbital (14 e-)

Orbitals: "pockets" within a subshell that had up to 2 electrons

Multiple Choice

How many shells are there?

• 2-12

• 5-9

• 1-7

• 10-10000000

Multiple Choice

How many electrons are in an S subshell?

• 2

• 5

• 1

• 10

Multiple Choice

How many orbitals are in a D subshell?

• 2

• 5

• 1

• 10

Multiple Choice

What orbital is Magnesium in?

• 2p

• 3d

• 2s

• 3s

Open Ended

Distinguish between a shell, a subshell, and an orbital…

1.5 - Electrons in atoms

Orbital diagrams:

Explain how electrons are arranged within an atom

Ex: Nitrogen

Ends in 2p (3 in on the 2p block)

Electrons configurations:

​Describe the arrangement of electrons in orbitals of an atom

Ex: Carbon

1s²2s²2p²

Valence electrons:

​Electrons in the outermost energy shell

Lewis dot diagram:

Main group electrons: Valence electrons from 1-8 as you move across a row on the periodic table

Multiple Choice

How many dots does Silicon have?

• 3

• 4

• 5

• 6

Chapters:

2.1 - Periodic Table Overview

2.2 - Periodic Table and atomic structure

2.3 - Periodic Trends

Unit 2: The Periodic Table

2.1 - Periodic Table Overview

• In 1860 scientists were searching for a way to arrange the 60 known elements that showed patterns in their properties.

• Dmitri Mendeleev Organized the elements into a periodic table by increasing atomic mass.

• Today, we order the by increasing atomic number

Horizontal row (1 - 7)​

Properties change in predictable manner across a period

Period

Vertical collom (aka families) (1 - 18)

Have similar chemical and physical properties

Ex: Sulfur = Group 16

Group

Groups Vs. Periods

Metals

Elements that have luster (shiny), conduct heat and electricity

Malleable - can be shaped into different forms

Ductile - can be stretched into thin wires

Mostly 1-3 valence electrons

Are solids at room temperature

Non-Metals

Dull elements, poor conductors of heat and electricity

Majority of elements in nature

Carbon is found in more compounds than all other elements combined

Most are gases

Solids (C, P, S, I, and Se) lack the luster of the metals (Br is liquid)

Lower melting point than metals

4-8 valence electrons

Metalloid

Some chemical and physical properties of metals and others of nonmetals

Are all lackluster solids and are poor conductors of heat and electricity

Behavior can be changed by using mixtures

Silicon and boron mixed = good electrical conductors

Fill in the Blanks

Multiple Choice

What are some key differences between Mendeleev’s periodic table and our modern periodic table?

• His: The properties of elements change in an orderly progression form Right to left

  Ours: left to right

• His: Increasing atomic mass

  Ours: Increasing atomic number

• He wasn't able to predict the

  existence and properties of elements that were

  still undiscovered at the time

• He originally organised elements in horizontal columns that showed similar

  physical and chemical properties

Multiple Choice

What group/period is Sulfur in?

• Group 9, Period 6

• Group 16, Period 3

• Group 2, Period 4

• Group 10, Period 2

Multiple Choice

Determine whether each of the following elements will have loose or tightly

held valence electrons.

1.) Potassium

2.) Sulfur

3.) Xenon

4.) Magnesium

• 1.) Loose

  2.) Tightly

  3.) Loose

  4.) Tightly

• 1.) Loose

  2.) Tightly

  3.) Tightly

  4.) Tightly

• 1.) Loose

  2.) Tightly

  3.) Loose

  4.) Loose

• 1.) Loose

  2.) Loose

  3.) Loose

  4.) Tightly