Lesson 1
Which is considered a physical change?
a) when a log is set on fire and becomes ash
b) when a log is cut in to small square pieces
B. When a log is cut into smaller pieces it changes the way it looks, but does not change what its made of (chemical composition)
What is an energy level?
One of the spaces around the nucleus of the atom.
What are radicals?
Radicals are a group of two or more atoms that acts like one atom.
What is an alchemist?
Early scientists from hundreds of years ago.
What is a reactant?
A substance that is changed in a chemical reaction.
What is a chemical change?
What is an ion?
An atom that has either a negative or positive charge.
What are chemical formulas?
A chemical formula tells the kind of atoms and how many of each kind are in a compound.
What is a mixture?
A mixture is made when substances are mixed and reaction takes place.
What is a product?
A substance that is formed in a chemical reaction.
How can you tell when a chemical change has happened?
Bubbles can appear; a solid may appear; light or energy may be produced.
What is the name of the first energy level?
K
What is the small number next to a letter in a chemical formula called?
Ex. H2O
Subscript
What chemical were alchemists trying to make?
Gold
What does it mean to balance an equation?
To keep the same number of atoms on each side of the equation.
The change in color in the statue of liberty - is it a chemical or physical change?
Chemical
copper and oxygen mixed making copper oxide.
How many electrons can the M energy level hold?
18
When a radical is present in a chemical formula, how is it written?
Between parenthesis
Ex. Ba(NO3)2
What is a solute?
The substance that is dissolved in a solution.
What does a chemical equation show?
A chemical equation shows the rearrangement of atoms that happens after a chemical change.
How many hydrogen molecules are in water? H2O
Two Hydrogen Molecules.
Which levels hold more electrons?
Closer to the nucleus OR Farther from the Nucleus
Levels farther from the nucleus hold more electrons than those closer.
Write a formula for a compound that has one atom of carbon and 2 atoms of oxygen.
CO2
What is a solvent?
The substance that can break down another substance.
When did nylon stockings appear in the market?
1939