Atoms, Molecules And Ion Flashcards
Based on dalton’s theory what is an atom?
An atom can be defined as the smallest particle of an element that can enter a chemical reaction.
What is the atomic theory?
Each element is made up of tiny particles called atoms and these atoms combine with each other to form chemical compounds. No atom is formed or disappears in a chemical reaction.
What is isotopic abundance?
The atomic mass or atomic weight.
Based on the carbon scale.
Most elements are complex and occur in nature as a mixture of two or more isotopes.
How is isotopes abundance found
It is necessary to know the masses of each isotopes and their percentages.
Formula-
Atomic number= (atomic mass 1) * %/100 + (atomic mass 2) * %/100
What is the mass spectrometer used for?
It is used to determine the relative masses of individual atoms. Positively charged ions are deflected and is inversely proportional to the mass of the ion.
What is Avogadro’s number
Is defined as the number of elementary particles per mol of a substance.
It is equal to 6.022 * 10^23 mol^- and the symbol is Na.
What are metals?
Are good conductors of heat and electricity and are malleable and ductile. (Thin and the ability to deform) . Most metals are solid at room temperature which gives it a silvery shine (expect for mercury which is liquid)
What are non metals
Non metals are usually poor conductors of heat and electricity and are not malleable and ductile. Many nonmetals are gases at room temperature ,while others are liquids and solids.
Gases at rtp - oxygen and chlorine
Soild at rtp - carbon,phosphor and sulphur
Liquid at rtp - Bromine (the only non meat Al that exists as a liquid at rtp)
What are metalloids
They are intermediate in their properties. In their physical properties, they are more like non metals, but under certain circumstances several of them can be made to conduct electricity and are known as semiconductors. Eg. Silicon
Periodic table
Elements in the same group show very similar properties.
Examples:
Lithium, sodium and potassium are all in group one (alkali) and reacts vigorously with water to produce hydrogen gas. (Charge of 1)
Beryllium, magnesium and strontium are all in group 2 (alkaline earth metals) and forms ions with a charge of 2 when they react with non metals.
Fluorine, chlorine and bromine are all in group 7(halogens) and react with non metals to form salts containing ions. (Charge of -1)
Group 8 (noble gases) form monatomic gases and have little chemical reaction.
What is electrical neutrality?
When the positively charged ions(cations) are equal to the total negatively charged ions (anions)
Name some metals that have multiple charges and give there charge
Copper- Cu+ or Cu2+
Iron - Fe2+ or Fe3+
Lead - Pb2+ or Pb4+
Manganese - Mn2+ or Mn4+
Tin -Sn2+ or Sn4+
Common cations(positively charged)
Iron: Fe3+ (ferric)
Iron:Fe2+ (ferrous)
Copper: Cu+ (cuprous)
Copper: Cu2+ (cupric)
Cobalt: Co2+ (cobaltous)
Cobalt: Co3+ (cobaltic)
Mercury: Hg2+ (mercuric)
Mercury Hg2^2+ (mercurous)
Note: mercury ions always occur bonded together
How to name monatomic anions?
To name a monatomic anion replace the suffix (ending) to -ide. This gives you the name of the anion (when the monatomic ion is negatively charged).
Examples:
Anion. Name
H- Hydride
F- Fluoride
Cl- Chloride
Br- Bromide
I- Iodide
O2- Oxide
N3- Nitride
P3- Phosphide
Different polyatomic ions
These ions are assigned special names that must be memorized in order to name the compounds containing them.
Examples:
NH4+ - ammonium
OH - : hydroxide
No3- : nitrate
ClO3- : chlorate
ClO4- : perchlorate
CN- : cyanide
CO3^-2 : carbonate
SO4^-2 : sulphate
CrO4^-2 : chromate
Cr2O7^-2 : dichromate
HPO4^-2 : hydrogen phosphate
PO4^-3 : phosphate
