Warm Up •What is a chemical reaction?

•How do you know there has been a chemical reaction?

Homework: Finish your project!!!

Notes:

• Chemical reactions- are when 2 or more COMPOUNDS combine chemically or break chemical bonds.

• Chemical reactions are written using the Element Symbols and any possible subscripts or coefficients.

Reactants → Products • The chemicals that go into a

reaction are called reactants. • The chemicals that come out are

called products. • The arrow (→) means “yields” or

“makes” or “produces”.

Let’s Label:

2Na + Cl2 2NaCl

products reactants

2Na + Cl2 2NaCl

products reactants

Coefficient

Coefficient

2Na + Cl2 2NaCl Coefficient is the BIG number in front. the number of molecules that are needed to balance it

More details…

• In all chemical reactions mass is conserved as reactants are transformed into products by the rearrangement of atoms.

Let’s watch a chemical reaction that is tasty! • http://www.sciencekids.co.nz/vi

deos/chemistry/chocolate.html

What does a chemical reaction look like?

Is the same # of atoms on

the Product

side?

Reactants: Carbon- 3 Hydrogen- 8 Oxygen – 10

Let’s Balance One Together

The Law of Conservation states that matter can neither be created nor destroyed. That means the atoms from one side have to show up on the other side!

How do you say it?

2 HCl + 2 Na → 2 NaCl + H2

You would say "two HCl plus two Na yields two NaCl and H two."

Bill Nye’s chemical reaction video!

• Write 5 facts from the video