Atoms, Elements, and Molecules
What is the smallest unit of matter?
atom
What takes up space and has mass?
matter
Changing a solid to a liquid
melting
A change in size, shape, or state is a ____________ .
physical change
The items that are reacting in a chemical reaction are called
reactants
I am made of only one kind of atom...
element
What are the three common states of matter?
solid, liquid, and gas
changing a gas to a liquid
condensation
The PE coaches added air to all of the basketballs, footballs, and volleyballs. Did they cause a physical or chemical change?
Physical change
The result of a chemical reaction is called a
product
A group of 2 or more atoms is a
molecule
My atoms are very tightly packed together
solid
What does thermal energy refer to?
heat energy
Bubbles forming in a chemical reaction is evidence of what type of change?
chemical change
What is the law of conservation of mass?
Mass cannot be created or destroyed
What are many atoms joined together in a repeating pattern?
complex molecules
My atoms are the farthest apart from each other
gas
Does the speed of water molecules move faster or slower when heat is added?
The speed of water molecules is faster when water is heated
Give two examples of a chemical change
Burning wood
Cooking an egg
Metal rusting
Leaves changing color
Burning sugar cubes
In the following chemical equation identify the reactants.
6CO2 + 6H2O → C6H12O6 + 6O2
Reactants = 6CO2 and 6H2O
How is the periodic table arranged?
increasing atomic number
Adding or removing thermal energy to a state of matter causes a ______________
change of state
What does a decrease in temperature cause molecules to do?
slow down and move closer together
What is the MAIN difference between physical and chemical changes?
Physical change - NO NEW SUBSTANCE
Chemical change - creates a NEW substance
In the following chemical equation identify the products.
6CO2 + 6H2O → C6H12O6 + 6O2
Products = C6H12O6 and 6O2