Metals and Non metals Flashcards
What is the difference between monatomic and diatomic elements?
- Monatomic consist of SINGLE uncombined atoms
ie. the noble gases; no need to form bonds - diatomic elements exists as 2 of same atoms bonded tog.
eg. Hydrogen, Oxygen, Nitrogen (subscript 2)
atomic number?
number of protons in nucleus
mass number?
number of protons and neutrons in nucleus
ion?
an atom/group of atoms that has gained or lost electron/s (has pos. or neg. charge)
what is ionic bonding?
- metal + non metal
- transfer of electrons leaves pos ion and neg ion
- the pos. ion (metal) and neg. ion (non metal) attract and combine to form an ionic compound (continuous + - lattice)
what properties differ metals from non metals
metals - shiny, malleable/ductile, good conductors of electricity, *SOLID at room temp. (except mercury)
non metals - dull, brittle, good insulators, *can be SOLID, LIQUID or GAS at room temp.
what group are alkali metals, halogens and noble gases
Alkali = group I
Alkali earth metals = group II
Halogens = group VII
Noble gases = group VIII
what does the period number and group number represent
period number = number of occupied shells
group number = number of valence electrons
Why do noble gases exist as single atoms
they have a full outer shell and are stable, therefore do not need to donate/accept electrons (so are unreactive)
What are the charges of simple ions
Group I = valance of 1+
Group II metals = valance of 2+
Group III metals = valance of 3+
(POSITIVE IONS)
Group VII non-metals = 1-
Group VIII non-metals = 2-
(NEGATIVE IONS)
What is covalent bonding/how does it work?
when non-metal atoms SHARE electrons to become stable (have full outer electron shell)
- pairs of electrons are shared by atoms
- forms molecule
What is a chemical reaction
- process involving successful collisions of particles to break chemical bonds + create new ones
- produces new substance and is hard to reverse
what is the rate of reaction?
- a measure of the amount of reactants being converted into products per unit time
what are examples of slow reactions + reactions favourable to be slow
- rusting
- chemical wearing of rocks
- decay of animals/plants
Favourable
- rusting
- spoiling of food
Examples of fast reactions + favourable to be fast
- combustion
- explosions
Favourable
- digestion in body
- cooking food
What are the 4 factors that can change a reaction
Temperature, surface area, concentration, catalysts
How is the rate of reaction changed by altering temperature
- higher temp = particles moving faster and increasing number of collisions per unit time AND force of collisions
- increases chance of successful collisions, thus rate
How is rate of reaction changed by altering surface area
- more surface area = more particles available for collisions per unit time
- increases chance of successful collisions, thus rate
how is reaction rate affected by altering concentration
- increasing concentration = more particles per unit volume, increasing collisions per unit time
- increase chance of successful collisions, thus rate
What is the effect of a catalyst on reaction rate
- speeds up reaction by lowering activation energy (provides alternate path)
- does not change frequency of actual collisions, only increases frequency of SUCCESSFUL collisions
- not changed, used up or consumed in reaction themselves
What is a biological catalyst and why does our body rely on it
- Enzymes (proteins that speed up chemical reactions in cells)
- allows reactions within body to happen at sufficient rate at body temp. for survival
what is the reactivity in relation to group/period
- decreases down a group
- increases across a period
what substance can slow down reaction
inhibitor
naming ions? - what is ammonium
NH₄⁺
what are examples of catalysts?
nickel placed in explosions??
what are examples of enzymes?
amylase in saliva speeds up breakdown of starch into glucose
