Ions & Bonding Flashcards
define atom
the smallest unit of matter that retains its properties
what are the 3 subatomic particles?
protons, neutrons and electrons
how is the mass number calculated?
number of protons + number of neutrons
how is the number of neutrons calculated?
mass number - atomic number
how is the atomic number calculated?
number of protons
define isotopes
variations of the same element with different numbers of neutrons
what subatomic particle affects the chemical properties of an element?
electrons
do the physical properties change depending on the different isotopes of an element?
yes
what physical properties vary between isotopes?
masses
densities
mpt / bpt
how is the average mass of an element calculated?
isotope 1 (abundance x mass/ 100) + isotope 2 (abundance x mass/100)
Define ion
charged atoms or molecules
which is positive and which is negative; cations and anions
cations are positive and anions are negative
Define bonding
the forces between particles that cause them to stick together
Define structure
the 3D arrangement of particles as a consequence of bonding
Define lattice
a repeating pattern of particles
Define discrete
individual particles not arranged in a pattern
Define allotropes
different structural forms of the same element (same chem. properties, different physical properties)
Halogens exist as…
diatomic molecules held together by a single covalent bond
What are the predicted properties of halogens?
- low mpt (weak IMFs)
- do not conduct
- soluble only in oil-like substances
What is the standard state color (aq) of:
F₂
Cl₂
Br₂
I₂
F₂ : (g) pale yellow (aq) colorless
Cl₂ : (g) pale green (aq) pale yellow
Br₂: (l) red/brown (aq) orange
I₂ : (s) grey (aq) brown/orange
What is the relationship of mpt from F₂ - At₂
mpt inscreases from F₂ to At₂ because the particles get bigger and there is a larger surface area (more IMFs)
Test 1 for halogens (damp blue litmus paper and starch)
Cl₂ damp blue litmus→red→white
Br₂ damp blue litmus→red→white
(slow)
I₂ starch→blue/black
Test 2 for halogens (hexane test)
Cl₂ hexane→colorless
Br₂ hexane→orange
I₂ hexane→pink
Cl₂ + H₂O→
Br₂ + H₂O→
HCl + HOCl
HBr + HOBr
What color did the reaction of Fe and Cl₂ glow?
red
What happens to the mpt to alkaline earth metals (group 2)?
the mpt decreases but it is always higher than Group 1 due to the higher magnitude of charge and more delocalised electrons
What happens to the reactivity of Alkaline group metals (group 2)?
the reactivity increases but it is always lower than group 1 because they need to lose 2 electrons, not just 1
What are the 4 properties of transition metals?
- high mpt (higher than group 1 & 2)
- high density
- variable charges (2+,3+, → 8+)
- form colored compounds
What are the colors of the following ions
Fe²⁺
Fe³⁺
Cu²⁺
Mn²⁺
Mn⁷⁺
Cr³⁺
Cr⁶⁺
Fe²⁺……………..green
Fe³⁺……………..orange/brown
Cu²⁺……………..blue
Mn²⁺…………….pink
Mn⁷⁺…………….purple
Cr³⁺………………green
Cr⁶⁺………………bright orange
Define inert
a full outer energy level which causes the atom to be unreactive
What are the properties of noble gases?
- very low mpt (weak inter-atomic forces)
- do not conduct
- insoluble in water
- no bonding, exist as single atoms
- full outer energy level
What are some of the uses for the following elements?
He
Ne
Ar
He………….balloons / air-ships (less dense than air)
Ne………….lighting (produces color with electricity)
Ar…………..light-bulbs (inert atmosphere)
What is electronic configuration?
(x,y,z)
How many energy levels do atoms have?
7
Why does the process of loss of electron require little energy?
1) electrons are located on the outside of an atom
2) electrons have small masses
How can the numbers of protons or neutrons be changed?
nuclear reactions
Why do atoms tend to lose or gain electrons?
to fully occupy their outer energy level
Where does ionic bonding occur?
in compounds containing a metal and a non-metal
GO MEMORISE THE TABLE MALU SENT TO YOU
ok…
Define ionic bond
electrostatic force of attraction between oppositely charged ions
Why do ions attract in multiple directions?
because they are spheres (causes formation of a lattice)
Describe structure of NaCl
lattice of alternating cations and anions held together by electrostatic forces
Define properties
characteristics of chemicals
What are some properties that substances can have?
1) mpt / bpt
2) electrical conductivity
3) solubility
4) malleability
What does the strength of forces between particles depend on?
1) magnitude of charge
2) radius or ions (size)
Define electrical conductivity
charged particles that can move without breaking forces
In what states can ionic substances conduct?
liquid or aqueous
What are the 4 properties of ionic substances?
1) high mpt
2) conduct as (l) or (aq)
3) dissolve in water
4) brittle
What does malleability depend on?
forces present when particles move
Where does covalent bonding occur?
in substances containing 2 or more non-metals
How can covalent bonding be shown on a diagram?
bonding diagram or displayed formula
Define covalent bond
the electrostatic attraction of 2 nuclei for a shared pair of electrons
What are the 2 types of forces in a covalent discrete structure?
1) IMFs (weak)
2) covalent bonds (strong)
What are the 3 properties of covalent discretes?
1) very low mpt
2) do not conduct
3) only soluble in oil-like substances
Why do covalent discretes have a very low mpt?
because the IMFs are easy to break and mpt depends on the physical sie of the molecules
Why do covalent discretes not conduct?
because there are no charged particles
Why are covalent discretes only soluble in oil-like substances?
because during dissolving, molecules do not dissociate, the molecules only separate, meaning that only the IMFs need to be broken
What are the 4 properties of SiO₂ (sand)?
1) very high mpt
2) doesn’t conduct
3) insoluble in all solvents
4) brittle
Describe the structure of SiO₂
lattice of atoms held together by strong covalent bonds, not IMFs
Pick the correct word to fill in the blanks:
words:【only one force/both forces】
Most covalent structures have ________________, covalent and/or discrete
only one force
What are the 3 properties of diamond?
1) very high mpt (~3500 Cº)
2) does not conduct
3) does not dissolve in any solvent
What are the only 3 covalent substances to have a lattice structure?
1) SiO₂
2) C in diamond
3) C in graphite
What are the properties of graphite?
1) high mpt
2) conducts electricity due to delocalised electrons
3) insoluble in every solvent
4) lubricant, layers can slide over each other without affecting the rest of structure
Where does metallic bonding occur?
metallic elements
Describe a metallic element
a lattice of cations surrounded by delocalised electrons held together by strong electrostatic forces
What are the 4 characteristics of metallic elements?
1) high mpt
2) conduct
3) insoluble in all solvents
4) malleable
What is the relationship with color from F₂→At₂?
color becomes darker
What is the relationship of alkali group 1 metals when moving down with mpt?
decreases
What is the relationship of halogens group 2 non-metals when moving down with mpt?
increases
What is the relationship of alkali group 1 metals when moving down with reactivity?
increases
nvm
