Periods, groups, and elements
What does the atomic number tell you on the periodic table?
The number of protons in the atom.
Define matter with a definite composition and characteristic properties.
Substance
One or more new substances will always be a product of this change.
Chemical change.
Hydrogen
H
What law states that in a chemical equation, the total mass of the reactants must equal the total mass of the products?
The Law of Conservation of Mass.
What part of an atom is in the nucleus and has a mass of 1 a.m.u.?
Protons.
Define matter made up of 2 or more substances, mixed together but keep their own properties.
Mixture
Cellular respiration can be described as what type of change?
Chemical change
Sodium
Na
What law states that every pure substance always contains the same elements combined in the same proportions by weight?
The Law of Definite Proportions.
What are the 3 basic categories of elements on the periodic table?
Metals, Non-metals, and semi-metals (metalloids).
Define matter made of 2 or more elements that are chemically combined.
Compounds
Is ice melting a physical change?
Yes
Potassium
K
A characteristic of a substance that describes its ability or inability to change into new substances is what type of property?
A chemical property
What group of the periodic table all violently react with water?
Group 1
What type of mixture is one that you can see all different parts of it?
Heterogeneous Mixture.
During a(n) _________ change, heat flows into the matter.
Endothermic
Silver
Ag
A self contained and isolated system in which matter cannot enter or exit is what type of system?
A closed system.
What is a special characteristic of group 18 on the periodic table?
They do NOT react with anything. Otherwise known as completely Inert.
What type of mixture is so thoroughly mixed that you cannot see the different parts?
Homogeneous mixture.
During a(n) ____________ change heat flows out of the matter.
Exothermic
Mercury
Hg
What is the most reactive element in existence?
Fluorine