Unit 1 Flashcards
What is the atomic number?
The number of protons in an atom’s structure.
What is the mass number?
The number of protons + neutrons in the atom’s nucleus.
Define Element.
Contains only one type of atom.
Define isotope.
Atoms with the same atomic number but different mass number.
(same number of protons as electrons, but different number of neutrons)
What is a molecule?
2 or more atoms chemically bonded together. (same or different)
Define a compound.
Two or more atoms of DIFFERENT elements chemically bonded together.
What is a mixture?
Two or more types of atoms, molecules, or compounds which AREN’T chemically bonded.
Define an ion.
A positively or negatively charged atom.
Define diatomic.
(to an element) An element/molecule which only occurs naturally in pairs.
What is a covalent bond and how is it held together?
A bond in which non-metal atoms are held together by a shared pair of electrons that are attracted to the positive nuclei of the atoms.
What is an ionic bond and how is it held together?
A bond between a metal and a non-metal, held together by oppositely charged ions.
What is group 1 called?
Alkali Metals
What is group 7 called?
The Halogens
What is group 0 called?
Noble Gases
What are the diatomic elements?
Iodine
Bromine
Chlorine
Fluorine
Nitrogen
Hydrogen
Oxygen
How are ionic bonds formed?
When a metal donates its outer electrons to a non metal
Do ionic substances conduct electricity and why?
Only when AQUEOUS (dissolved in water) or MOLTEN (melted)
This is because the ions are free to move.
Why do covalent molecules have low boiling and melting points?
Because their INTERMOLECULAR FORCES are weak and break easily.
How and why are ions formed?
Ions are formed when atoms lose or gain electrons in order to become stable.
Define a diatomic element.
An element which only naturally exists as a pair.
Why can graphite conduct but diamond can’t?
Graphite has delocalised electrons which move between layers, allowing electricity to flow.
What charge is the nucleus of an atom?
Positive
What are the four shapes of molecular bonds?
Linear
Angular
Trigonal Pyramidal
Tetrahedral
What is formula mass?
The MASS of a CHEMICAL FORMULA.
How are elements arranged on the periodic table?
In order of INCREASING ATOMIC number
What are the horizontal rows on the periodic table called?
Periods
What are the vertical columns on the periodic table called?
Groups
What does it mean when elements are in the same atomic group?
They have SIMILAR CHEMICAL PROPERTIES
Where are the nonmetals located on the periodic table?
On the right side (after staircase)
Where are the METALS located on the periodic table?
On the left side (left of staircase)
What is all matter made up of?
Atoms
Define an element.
A SUBSTANCE that contains only ONE TYPE of atom
What particles are found in the nucleus?
Protons and Neutrons
Where are electrons located?
In the electron shells
What is the mass of an electron?
0 AMU
What is the mass of a proton?
1 AMU
What is the mass of a neutron?
1 AMU
What is the charge of a proton?
+1 (Positive)
What is the charge of a neutron?
0 (Neutral)
What is the charge of an electron?
-1 (Negative)
What is the atomic number?
The number of protons in an atom.
What is the mass number?
The number of Protons + Neutrons in an atom.
Why do atoms have no charge?
Atoms have no charge because they have equal amounts of protons and electrons, which balance each other.
Why do elements in the same group have similar properties?
Elements in the same group have similar properties because they have the same number of outer electrons in their outer shell.
How should you write electron arrangement?
PAGE 6 OF DATA BOOKLET
Going from innermost shell to outermost shell, in clockwise direction.
What is an isotope?
An isotope is an atom with the same atomic number as the original element but a different mass number.
TLDR; Same atomic number, varied mass number.
When going down a period on the periodic table, how is reactivity affected in METALS?
Reactivity INCREASES as you go down a group of METALS.
When going down a period on the periodic table, how is reactivity affected in NON-METALS?
Reactivity DECREASES as you go down a group of NON-METALS.
What is the reactivity of the noble gases?
They are inert/unreactive
What is the top number in nucleide notation?
MASS number
What is the bottom number in nucleide notation?
Atomic number
What should nucleide notation show?
Atomic Number
Mass Number
Charge
How do you calculate RAM (relative atomic mass)?
RAM =
(mass of isotope A x %) + (mass of isotope B x %)
——————————————————-
100
What does the suffix “-ide” mean?
2 element compound
What does the suffix “-ate” mean?
2 Elements + Oxygen (a lot)
What does the suffix “-ite” mean?
2 Elements + Oxygen (a little)
What are the exceptions to the “-ide”/”-ate” rule?
Magnesium Hydroxide = MgH2O2
Ammonium Chloride = ClH4
How can chemical formula be calculated?
SVSDF
How do calculate formula if prefixes are involved?
Ignore valency
What is a word equation?
An equation with the full names of each reactant and the products they form written out.
ie. Magnesium Oxide + Hydrogen –> Magnesium Hydroxide
What does the term aqueous mean?
Dissolved in water
What are roman numerals used for?
The valency of transition metals.
What does a chemical formula tell you?
The types of atoms in a molecule and how many there are of each.
What does the formula of a covalent network do?
It gives the simplest ratio of each atom in the network.
What is an ion?
A charged atom
How do you balance a chemical equation?
By changing the coefficients
Define a compound.
Two or more atoms of DIFFERENT elements which are chemically bonded together.
(A compound is a molecule)
What type of elements are covalent bonds between?
Non-metals and non-metals
What is a covalent bond?
A chemical bond formed when two or more atoms share electrons.
What holds covalent bonds together?
Covalent bonds are held together by two or more shared outer electrons and their attraction to the positive nuclei involved.
What is ionic bonding?
Transfer of electrons
Which elements form ionic bonds?
Metals and non-metals
Do metals give or take electrons in bonding?
Give/lose
Do non-metals give or take electrons?
Take/gain
What type of ion do metals form?
POSITIVE ions (+1)
What type of ions do non-metals make?
NEGATIVE ions (-1)
What holds an ionic bond together?
Electrostatic attraction between the positive and negative ions
What is a covalent network?
A very large structure of covalently bonded atoms.
Properties:
HIGH melting point
DOES NOT conduct electricity (excluding graphite)
Name 5 examples of covalent networks:
- Carbon (ONLY diamond and graphite)
- Boron
- Silicon
- Silicon Dioxide (Quartz)
- Silicon Carbide
How are carbons shaped in diamonds?
Tetrahedral shape
Name all of the diatomic elements.
BICHONF
Bromine
Iodine
Chlorine
Hydrogen
Oxygen
Nitrogen
Fluorine
Name all molecular shapes.
Linear
Angular
Pyramidal
Tetrahedral
What are intermolecular forces?
Intermolecular forces are the forces found in between molecules.
Describe the intermolecular forces of a covalent molecule.
Intermolecular forces between a covalent network are WEAK.
List the ways you can increase the rate of a reaction.
- Increase temperature
- Add a catalyst
- Increase the concentration of reactant
- Decrease in particle size/increase of surface area
Define a catalyst.
A catalyst is a substance which speeds up chemical reactions, but can be recovered while CHEMICALLY UNCHANGED at the end of a reaction.
How can you calculate the rate of reaction?
∆ Quantity / ∆ Time
How would you calculate the mass of a mole of any substance?
Gram Formula Mass (GFM)
How do you calculate GFM?
By adding up all of the RAMs inside the compound
What is the mass of 2 moles of NaCl?
GFM:
•Na- 1 x 23 = 23
•Cl- 1 x 35.5 = 35.5
GFM= 23 + 35.5 = 58.5g
Sub into Formula:
n=m/GFM
2= m/58.5
Solve:
m= 2 x 58.5
m= 117g
How can calculations be performed using the relationship between the mass and the number of moles in a substance?
N = m/GFM
N — Number of Moles
m — Mass
GFM — Gram Formula Mass
How can calculations be performed using the relationship between volume, concentration and number of moles in a substance?
N = cv (litres)
N — Number of Moles
c — Concentration
v — Volume
Calculate the volume of a 2 molL-1 solution containing 0.1 moles of solute
n=CV
V=n/C
V= 0.1/2
V=0.05L
Calculate the mass of 500 cm3 of a 2 molL-1 solution of K2CO3
GFM:
• K2- 2 x 39= 78
• C- 1 x 12= 12
• O3- 3 x 16= 48
•GFM=78+12+48= 138g
Sub into Formulae:
• C=2 n=? V= 500cm3= 0.5 LITRES
• n=? m=? GFM= 138g
Solve first equation:
n=CV
n= 2 x 0.5
n= 1 mole
Use info to solve second equation:
n=m/GFM
m= n x GFM
m= 1 x 138
m= 138g
Define solvent.
The SUBSTANCE that DISSOLVES the SOLUTE.
Define solute.
A solute is a substance dissolved in a solvent to create a solution.
Define solution.
The result of a solute dissolved in a solvent.
What is the pH scale?
An indication of the hydrogen ion concentration.
Runs from 0 to 14.
<7 acid
7= neutral
>7 alkaline
Name a feature of neutral solutions.
Have equal concentrations of H+(aq) and OHˉ(aq) ions.
Name the features of acids.
- HIGHER concentration of H+(aq) ions than OHˉ(aq) ions
- <7 pH
Describe the relationship between quantities of OHˉ ions and the periodic table.
As you go HIGHER in the periodic table (towards 14), the quantity of OHˉ ions INCREASES and H+ DECREASES.
Describe the relationship between quantities of H+ ions and the periodic table.
As you go LOWER in the periodic table (towards 0), the quantity of H+ ions INCREASES and OHˉ(aq) DECREASES.
Between two, what is the more common ion in ALKALIS?
Alkalis have a HIGHER concentration of OHˉ ions than H+ ions.
Between two, what is the more common ion in ACIDS?
Acids have a HIGHER concentration of H+ ios than OHˉ ions.
Name the features of alkalis.
- Higher concentration of OHˉ ions than H+ ions
- > 7 pH
What is the equation for the disassociation of water?
H2O(l) <–> H+(aq) + OH-(aq)
What do all acids contain?
Hydrogen
What happens when you dilute an acid with water?
- pH INCREASES towards 7 (water is neutral)
- DECREASES the concentration of H+ (aq) ions.
What happens when you dilute an alkali with water?
- pH DECREASES towards 7
- DECREASES concentration of OHˉ (aq) ions.
What do SOLUBLE NON-METAL OXIDES form when dissolved in water?
ACIDIC solutions
What do SOLUBLE METAL OXIDES form when dissolved in water?
ALKALINE solutions.
State the equation for SOLUBLE METAL OXIDES dissolving in water?
Metal oxide + Water → Metal Hydroxide
Define a BASE.
A substance that reacts with an acid to make water.
List examples of bases.
- Metal Oxides
- Metal Hydroxides
- Metal Carbonates
- Ammonia
What do SOLUBLE BASES form when dissolved in water?
Alkaline solutions.
What is a neutralisation reaction?
A neutralisation reaction is a reaction in which a BASE reacts with an ACID to form WATER. One of the products is SALT.
State the equation for the neutralisation reaction of metal oxide.
Metal oxide + Acid → Salt + Water
State the equation for the neutralisation reaction of metal hydroxide.
Metal hydroxide + Acid → Salt + Water
State the equation for the neutralisation reaction of metal carbonate.
Metal carbonate + Acid → Salt + Water + Carbon dioxide
How are salts named?
Prefix — The NON-ACID
Suffix — The ACID NAME
Define a SPECTATOR ION.
A spectator ion is an ion that is present during the reaction but remains unchanged by the reaction.
State the neutralisation equation for magnesium reacting with hydrochloric acid.
Hydrochloric acid + Magnesium —> Magnesium chloride + water
HCl + Mg -> MgCl2 + H2O
How are carbons shaped in graphite?
in LAYERS of HEXAGONS.
What is the melting/boiling point of covalent networks and why?
Covalent networks have a very high melting and boiling point because their covalent bonds are strong and take a lot of energy to break.
What is the melting/boiling point of covalent compounds?
Very low because their covalent bonds are weak.
What is the melting/boiling point of ionic compounds?
Ionic compounds have a high melting and boiling point because they have strong intermolecular forces.
What state are ionic compounds in while at room temperature?
Solids.
Can covalent compounds conduct electricity?
No (except Graphite)
Can covalent networks conduct electricity?
No (excluding Graphite).
Can ionic compounds conduct electricity?
Only when in molten or aqueous state.
What state are covalent compounds at in room temperature?
Any.
Are covalent networks soluble?
No.
Are ionic compounds soluble in water?
Most, but not all, are.
Why can ionic compounds conduct electricity but only as aqueous or molten?
Molten or aqueous ionic compounds conduct electricity because the freely moving ions carry charge.
What is the formula for sulfuric acid?
H2SO4
What is the formula for nitric acid?
HNO3
Define titration.
Titration is a method in which a solution of KNOWN CONCENTRATION is used to determine the concentration of an UNKNOWN SOLUTION.
Metal Oxide + Acid —>
Salt + Water
Metal Hydroxide + Acid —>
Salt + Water
Metal Carbonate + Acid —>
Salt + Water + Carbon Dioxide
How are elements arranged in the periodic table?
In order of increasing atomic number.
