Chemical change
Name a few examples of chemical change?
iron rust, gas burning, eggs cooking, bread rising
What are the three states of matter?
Solid liquid gas
This is the basic unit of matter
atoms... uncuttable
This is the factor that a scientist changes on purpose in an experiment.
independent variable
This is the number of protons in an atom and determines its place on the Periodic Table
atomic number
How do we know a Chemical change happened? What are signs of a chemical change?
When a new substance is formed. Evidence of this change includes a change on odor, change in color, bubbles, or heat given off
Describe what happens during a physical change
This type of change does not produce a new substance and often includes changes in state or form.
This subatomic particle has a positive charge and the # of these defines what element it is!
Protons
This is the factor that is measured in an experiment.
Dependent Variable
Name the element that has the chemical symbol “Li”? "O"?
Lithium; Oxygen
When we mix zinc and hydrochloric acid, what is the gas that is produced? What is a property about this gas?
H2 Hydrogen gas is produced, it is flammable
What are some examples of physical change?
boiling water, dissolving sugar, dicing fruit or vegetables, melting snow
These tiny particles that are not in the nucleus and have a negative charge.
electrons
These are all the variables that must be kept the same to ensure a fair test.
controlled variables
These elements are located on the "stair-step" line and have properties of both metals and nonmetals.
metalloids
What is produced when burning steel wool?
Iron oxide or rust, Fe2O3
What is an example of evaporation?
Drying clothes, disappearing puddles, sweating; steam from a shower, water cycle, drying a mopped floor
This number tells you how many protons are in an atom and determines the element.
atomic number
This group does not receive the independent variable and is used for comparison.
Control group
What do subscripts tell us when we use element symbols to write chemical formulas?
the number of atoms of each element present in a molecule or compound
Mixing baking soda and vinegar will create what type of gas?
Carbon Dioxide
What is solubility?
Solubility is a physical change. Solubility is the ability of a substance to dissolve in a solvent (water) to form a solution
How many protons does a hydrogen atom have?
1, and it does not have a neutron!
This term describes a prediction that can be tested through experimentation.
hypothesis
Why is O2 a molecule and not a compound?
it is made of only one type of element (oxygen). A compound, in contrast, is a pure substance formed from at least two different elementsExothermic reactions.