Chemistry 15-17 Flashcards
Everything is made up of chemicals either in the form of…
Pure elements or more commonly in the form of compounds
Pure substances that cannot be broken down into other substances
elements
There are about…
90 naturally and 25 synthetic elements
Based on their properties all elements are divided into 3 classes…
Metals, non-metals, and metalloids
A shiny, malleable ductile element
metals
Metals make up…
most elements
Metals are good conductions of…
Electricity and heat
Metals are…
Silver/grey and shiny
All malleable items can be…
Beaten or rolled into sheets without crumbling
All ductile materials can be…
Stretched into long wires
Metals are solid at
25 degrees
Some are highly reactive with…
Air and water other are unreactive
17 elements with varying properties that are different from metals
non-metals
Grouped together because…
They are different from metals
Non-metals vary
in colours and forms
Non-metals half exist as connected groups of atoms called…
Molecules, some only as individual atoms
Elements with properties between metals and non-metals
metalloids
Some metalloids conduct electricity but…
Not very well
A group of non-metal atoms bound by covenant bonds
molecule
Organizes all the elements according to their…
chemical properties
Metals located from the left side to the…
Centre of the table
Non-metals on…
Far right
A non-metal but located on the left because it behaves like a metal in chemical reactions
hydrogen
Period 1-7
horizontal row
Group or family 1-18
vertical column
Families of groups of elements that have…
Similar chemical and physical properties
Group 1 includes lithium, sodium and…
potassium
Alkali Metals…
Very reactive with water
Group 2 includes magnesium and…
Calcium
Reactive but not as alkali metals, less soluble than compounds formed by alkali metals
Alkaline Earth Metals
Group 18 contains helium, neon and…
Argon which are noble gases
Noble gases…
Non-reactive
Group 17 are the halogen, which consists of flourine, chlorine, bromine and…
Iodine
Poisonous, react with the alkali metals to form salts – compounds produced in neutralization reactions between acids and base
halogens
The smallest part of an element that still has the properties of the element.
atomic
Region of spaces near an atoms nucleas that may be empty or may contain electrons
energy levels
Electrons in energy levels nearest to the nucleas have…
The lowest energy levels
Electrons farther away from the nucleas…
Have more energy
First energy levels can hold up to…
2 electrons
2nd and 3rd levels can hold up to
8 electrons
The atomic number of an element indicates the number of protons it has all atoms have an element of the same number of protons
atomic number
Atoms of the same element that contain different numbers of neutrons.
isotopes
each isotope of an element is given a number called the
mass number
An integer equal to the total number of protons and neutrons in the nucleas of an atom
mass number
To determine the number of neutrons in an atom by
Subtracting the atomic number from the mass number
Related to mass number, the average mass of the elements isotopes
atomic molar mass
Number of electrons in an atom =
The number of protons
The process of gaining or losing electrons
ionization
electrically charged atom or group of atoms
ion
Positively charged ions
cation
Cations usually form when the metal atoms
lose electrons
When electrons leave an atom
negative charges leave, the ions remain positively charged
Has more protons than
electrons
Negatively charged ions
anions
Mostly form when non-metals gain
electrons
Written by using the first part of the elements name and changing the end to
“ide”
An element reactivity is related to the number
of electrons in it’s outer energy level
elements are most stable, or unreactive when they have filled
the outer energy levels
very stable, do not lose or gain electrons
noble gases
Electrons in the outer energy level
valence electrons
The tendency to gain or lose electrons
valence
Used to describe the number of electrons an element can gain or lose to combine with other elements
valence number
Elements in the same family have the same
number of valence electrons, resulting in similar chemical properties.
From left or right on the periodic table, atoms gain one valence electrons
and proton per element
States that atoms bond in such a way as to have eight electrons in their valance energy levels
the octect rule
This is another way to say that atoms tend to be stable with
full outer energy levels
Hydrogen, lithium, and beryllium only need two electrons in their
Valence level because the nearest noble gas, helium, has 2 electrons
It is difficult for atoms to lose more than three electrons because
every time an electron is lost the nucleas, the nucleas makes the remaining electrons tighter
Protons
atomic number
Electrons
atomic number - charge
Neutrons
Mass number - atomic number
an organized array of ions
crystal lattice
A neutral; smallest amount of an iconic compound with the composition shown by the chemical formula
formula unit
multiple atoms of the same element
polyatomic molecule
Atoms can exist on their own
monatomic molecule
mono
1
di
2
tri
3
tetra
4
penta
5
hexa
6
hepta
7
octa
8
ennea
9
deca
10
identify ionic compounds
always contain positive and
negative ions
presence of a
cation
formula begins with a
metal ion
good
conductors
identify molecular compounds
groups of non-metallic atoms
neici together by bonds
crystal
shape
conducts
electricity
polar =
each molecule has a positive and negative end
living system depend on
polarity
polarity makes it easier to be a
liquid
electrolytes
any solution that can conduct electricity
compound that dissolves water to form of solution with a PH LOWER THAN 7
acid
compound that dissolves in water to form a solution with a PH HIGHER THAN 7
base
a measure of the number of hydrogen ions in a solution
H
A substance that can keep a PH nearly constant despite added acids and bases
Buffer
In acid blue litmus paper turns red
Litmus indicator
In base red litmus paper turns
blue
neutral solution will
not change colour
A mixture of several indicators that change colour as acidity changes
Universal indicator
the presence of a hydrogen ion with a metal ion or allumonium ion
indicates that a substance is basic
When acids and bases react and both a acidic and basic properties disappear produces water and compound – salt
Neutralization
2 most hazardous recreation chemicals
- alcohol 2. Nicotine
