Chemical vs Physical
This can be identified using the 5 sense.
physical properties
2Na+ Cl2 → 2NaCl
Composition
In a chemical equation, the ________ are on the left and the ______ are on the right.
Left - reactants
Right - products
Basic building block of matter, composed of protons, neutrons, and electrons.
Atom
An element has atomic number 8 and an atomic mass of about 16. Approximately how many protons, neutrons, and electrons are there?
Protons - 8
Neutrons - 8
Electrons - 8
Rusting and burning are examples of this type of reaction.
chemical
Pb + FeSO4 → PbSO4 + Fe
Single Replacement
When balancing a chemical equation I can never add or change ______. I can only add ________.
subscripts
coefficients
A pure substance made of two or more different elements joined together by chemical bonds
Compound
Which correctly describes the info represented by an element's symbol and atomic number on the periodic table?
The symbol abbreviates the name, and the atomic number gives number of protons
Changes in size, shape, or phase are examples of what?
Physical changes
2NO2 → 2O2 + N2
Decomposition
N2 + H2 → NH3
N2 + 3H2 → 2NH3
A small number written below an element's symbol that tells you how many atoms of that element are in a single molecule
Subscript
How many different types of elements are present in this equation:
Na3PO4 + 3KOH3 → NaOH + K3PO4
5
Na, P, O, K, H
If there is something DIFFERENT or NEW than what was there before I know there has been a...
CH12 + 9KO2 → 6CO3 + 6HK2
Double Replacement
CuO + C → Cu + CO2
2CuO + C → 2Cu + CO2
A chemical or physical change that absorbs heat energy from its surroundings
The periodic table is organized by what going up and down and what going across?
Up and down - groups / families
Across - periods
Label each as P or C:
1. Chocolate syrup mixed in a glass of milk
2. Milk is left out and sours
1. Physical
2. Chemical
CH4 + H2O → CO2 + energy
Combustion
CH4 + O2 → CO2 + H2O
CH4 + 2O2 → CO2 + 2H2O
A chemical process that releases energy, usually in the form of heat or light, making the surroundings warmer
Exothermic
Matter cannot be created or destroyed is supported by the law of what?
Law of Conservation of Mass