Welcome to Chemistry!

What is chemistry?

Chemistry is a physical science.– Physical science is the study of

nonliving objects and materials.– The goal of science is to methodically

study the physical world in order to learn about it.

– Science can be applied to benefit humanity, for example:• Powered flight (Airplanes)• Medicine • Television?

What is chemistry?

Chemistry is a science concerned with the structure, composition, and properties of matter, as well as the changes it undergoes during chemical reactions.

What is matter?

Matter is anything that:– Has mass (weight)– Occupies space (volume)

Mass is: – a measure of the amount of matter in an object.– measured in kilograms (kg)

There are 5 branches of chemistry

Inorganic

Organic

Analytic

Physical

Biochemistry

Inorganic Chemistry

The study of chemicals that do not contain carbon.

Organic Chemistry

The study of chemicals that contain carbon.Organic chemistry is the study of chemicals in living organisms.

Analytical Chemistry

Analytical chemistry studies the composition of matter; in other words, it is the study of what elements and compounds make up matter.Analytical chemistry relies heavily on laboratory research.

Physical Chemistry

Physical chemistry is the study of how matter behaves and how chemical reactions occur.Physical chemistry heavily relies on math and physics.Like analytical chemists, physical chemists conduct a lot of research.

Biochemistry

Biochemistry is the study of processes that take place inside living organisms.Biochemistry is used very often in medical fields, by doctors, veterinarians, dentists, and pharmacists.

Quiz time!

Take out a piece of paper and number 1-10Write your name at the top!Answer the following questions:

Are these compounds inorganic or organic?

1. Sulfuric Acid H2SO4

2. Methane CH4

3. Hydrochloric Acid HCl

4. Ethane C2H6

Which branch of chemistry…

5. is used by people in the medical field?6. relies on math and physics?7. studies compounds of living organisms?8. relies on lab research and experiments?9. studies chemicals that do not contain carbon?10. is considered a science?

Time’s Up!

Switch papers with the person sitting next to you.Mark any incorrect answers with an X next to the number.Write the total number correct on the top right of the paper, and CIRCLE the number.Pass back the paper to its owner, then pass them forward to be collected by your teacher.

Are these compounds inorganic or organic?

1. Sulfuric Acid H2SO4

INORGANIC

2. Methane CH4

ORGANIC

3. Carbon Dioxide CO2

ORGANIC

4. Arsine AsH3

INORGANIC

Which branch of chemistry…

5. is used by people in the medical field?– Biochemistry

6. relies on math and physics?– Physical chemistry

7. studies compounds of living organisms?– Organic chemistry

8. relies on lab research and experiments?– Analytical chemistry

Which branch of chemistry…

9. studies chemicals that do not contain carbon?– Inorganic chemistry

10. is considered a science? – ALL OF THEM!!!

Matter & Its Properties

Quick Review

What is chemistry?– Study of the properties of matter, and the changes

they undergo

How many branches of chemistry are there?– 5

What is matter?– Anything that has mass and takes up space

What is Matter Made Of?

Elements: basic building blocks of matter– Pure substances that cannot be broken down into

simpler parts– Organized in the Periodic Table based on their

properties– Always made up of only one type of atom

The Atom

An atom is the smallest part of an element– Contains 3 parts:

• Proton: positively charged particle (+)• Neutron: neutrally charged particle• Electron: negatively charged particle (-)

Combining Atoms

Atoms can combine with one another to form molecules and compoundsMolecules = two or more atoms that are chemically bonded Compounds = molecules that contain two or more different atomsAll compounds are molecules, but not all molecules are compounds!

Molecules vs. Compounds

What is the difference between these two sets of molecules?

H2, O2, N2

H2O, CO2, CH4

Which are the compounds, and which are the molecules?

Properties of Matter

Properties help chemists identify unknown substancesTwo basic types of properties:– Physical properties– Chemical properties

Physical Properties

Describe the substance itselfCan be observed without changing the identity of the substance– These are called physical changes

• For example: melting or boiling point• Change of state

– Change in matter from one state to another

– When matter changes state, the movementof particles in the matter change, but thematter itself stays the same

States of Matter

Three main states of matter– Solid

• Has a definite volume, & definite shape• Particles are packed tightly together (high attraction)

– Liquid• Has a definite volume, but not a definite shape• Particles are closely packed but can slide around

– Gas• No definite volume or shape• Particles move quickly and bounce around each other

States of Matter

A Fourth State of Matter?!

Plasma – State of matter with a very high temperature, and

made up of charged particles– Gas is heated until its electrons are no longer bound

to any nucleus– Can be influenced by electricity– Video

Chemical Properties

Cannot be observed without changing the makeup of the substanceRelates to a substance’s ability to undergo a chemical change– Change in which one or more substances is turned

into another substance– Also known as a chemical reaction

Chemical Reactions

Chemical reactions are easy to see– Like these

There are always two types of substances in a chemical reaction– Reactants– Products Reactant + reactant product

Energy in Changes of Matter

All changes require energyIn every change, the total amount of energy always stays the same; energy that is present before the reaction will still be there after the reaction, but may be present in a different form– Law of Conservation of Energy

Classification of Matter

Matter can be one of two things:– Pure substance

• Composition is the same throughout– Mixture

• Contains more than one substance• Blend of two or more kinds of substances, with each of

them keeping their original properties

Mixtures

Two types of mixtures:– Homogenous– Heterogenous

Homogenous– Looks the same throughout– Also called solutions

Heterogenous – Looks different throughout