atomic structure Flashcards
difference between alkali metals (group 1) and transition metals
trans metals are denser and stronger
have higher melting points
alkali have higher atomic volumes
trans have higher masses
what type of metal is copper?
a trans metal
describe difference in reactivity (ions) between metals and non-metals
metals react to form positive ions
non reacts to form negative ions
is lithium or potassium more reactive
explain
potassium
-as u go down the group more reactive
-outer shell more far away,
-less attracted to nucleus
-therefore easier to lose outer electron
how is periodic table diff to mendeleev one
arranged in proton number not atomic weight
how did mendeleev keep his periodic table up for adaptation
he left gaps for undiscovered/ predicted properties
explain the process of fractional distillation to separate a mixture of the liquids methanol, ethanol and propanol
Heat is applied and the liquid with the lowest boiling point evaporates and condenses into a beaker.
If other liquids evaporate by chance, they condense in the fractionating column back into the flask.
The temperature is altered to repeat the process for the second liquid.
The three liquids are separated based on differing boiling points with the third remaining in the flask.
substances that can react with an acid to form a soluble salt
-metal
-metal oxide
-metal hydroxide
-metal carbonate
Describe a method to make pure, dry crystals of magnesium sulfate from a metal oxide and a dilute acid.
- use magnesium oxide and sulfuric acid
- add sulfuric acid to a beaker
- warm sulfuric acid
- add magnesium oxide
- stir
- add til magnesium oxide in excess
- filter
- using a filter paper and funnel
- to remove excess magnesium oxide
- heat solution in an evaporating basin
- to crystallisation point
- leave to crystallise
- pat dry with filter paper
what was atomic theory
the idea that everything is made up of tiny particles that can’t be split up anymore, separated by empty space - democritus
desc history of the atom
JOHN DALTON
-suggested diff types of sphere make diff elements
JJ THOMPSON 1897
-experiments concluded atoms not solid sphere, measurements of mass and charge showed ball of positive charge w/ electrons stuck in it
RUTHERFORD 1909
-alpha scattering, too deflected, so came up with most mass concentrated in the middle ( +ve nucleus) with cloud of electrons
BOHR
-scientists realised cloud of electrons would collapse, BOHR suggested electrons orbit in fixed shells
CHADWICK
-proved existence of neutrons
differences betw iron (trans metal) and sodium (gr 1)
- iron has a high(er) melting / boiling point
- iron is dense(r)
- iron is hard(er)
- iron is strong(er)
- iron is less reactive
- iron has ions with different charges
- iron forms coloured compounds
- iron can be a catalyst
Explain the trend in boiling points of the halogens
(b.p) increases down the table
(because) the size of the molecule increases
(so) the intermolecular forces increase (in strength)
more energy is needed to overcome the intermolecular forces
boiling point is a ….
(property)
…bulk property