Elements and atoms Flashcards
What is a compound?
Two or more elements and/or compounds chemically joined
What is a mixture?
Two or more elements and/or compounds mixed together but not chemically joined
What is an element?
A substance that cannot be broken down into other substances
What is a molecule?
two or more chemically joined atoms
In the periodic table, what is a row also called?
A period
In the periodic table, what is a collumn also called?
A group
In the periodic table, how do you group elements into groups?
Elements with the same number of electrons in the outer shell are in the same group
In the periodic table, how do you group elements into periods?
Elements with the same number of shells are in the same period
What is an atom?
The smallest part of an element that can exist
What is a chemical formula?
A formula that shows the relative amounts of atoms of each element in a compound
What is a chemical symbol?
A one-letter or two-letter code used by scientists in all countries
All metals take the shape of…
… A lattice
Copper sulfate + iron ->
iron sulfate + copper
What do you add to the end of an element in a compound if it has oxygen in it?
-ate (Sulfur->sulfate)
What do you add to the end of an element in a compound if it doesn’t have oxygen in it?
-ide (Sulfur->sulfide)
What is a lattice?
A regular array of particals
When metals and non-metals join together, what shape do they take?
A lattice
When non-metals bond together, what shape do they (almost) always take?
A gas molecule
What is a shell?
Where you find the electrons in an atom; outside the nucleus
How many electrons does the first shell hold?
2
How many electrons does the second shell hold?
8
How many electrons does the third shell hold?
18 (pretend it’s 8 though)
How many electrons does the fourth shell hold?
32
What is the nucleus? (chemistry)
Where you find the protons and the neutrons in an atom
What is the formula for amount of neutrons?
Mass number - atomic number = neutrons
What is an atomic number?
The amount of protons
Which direction do periods run in the periodic table?
Horizontally
Which direction do groups run in the periodic table?
Vertically
What are the group 2 metals called?
Alkali Earth metals
An acid + a metal ->
Salt + hydrogen
An acid + a metal carbonate ->
Salt + water + carbon dioxide
Water + a metal ->
Metal hydroxide + hydrogen
Why is hydrogen in the middle of the periodic table?
It does not have the reactive metal properties of group 1
