Atomic structure and periodic table Flashcards
What is the difference between an atoms/elements and compound?
An atom is the smallest part of an element
An element is a substance that only contains one sort of atom
A compound contains two or more elements
What is a mixture?
Mixtures consist of 2 or more elements or compounds which is not chemically combined
What the difference between simple distillation and Fractional distillation?
SIMPLE DISTALATION-Obtain a solvent from a solution
FRACTIONAL DISTILLATION-separate mixtures in which the components have different boiling points
Models of the atom
pre 1900-tiny solid sphere that could not be divided
Plum pudding-a ball of positive charge with negative electrons embedded in it
What was Ruthford’s gold foil experiment?
Most alpha particles passed through
few were deflected by the positive nuclease
Tiny number of particles reflected back from the nucleus
What is an isotopes?
IONS-metal atoms lose electrons to form positive ions
non-metal atoms gain electrons to form negative ions
How did Mendeleev develop the periodic table?
columns-groups
MENDELEEV-he left gaps for elements that had not been discovered, he predicted elements by the existence of elements and their properties
What are the properties of the nobles gases
(group 0)?
full outer shell of electrons
unreactive to non-metal due to a full outer shell
boiling points increase down the group
What are the properties of an alkali metal (group 1)
1 electron in their outermost shell
soft metals, low density
low melting and boiling points decrease down the group
moving down the group the outer electron is less attracted to the nuclease and easier to lose
what is the structure of group 7?
non-metals
7 electrons in their outer shell
form molecules with 2 atoms joined by a covalent bond
What are the properties of transitions metals?
form coloured compounds ions with different charges can be used as catalyst good conductors of heat and electricity and can easily be shaped hard , strong metals high melting points high density
What is the difference between crystallisation and filtration?
FILTERATION-separate soluble solids from insoluble solids
CRYSTALIASATION-obtain a soluble solid from a solution
What separation technique is used to separate colours?
CHROMOTOGRAPHY-separate different soluble coloured components of a mixture
What is the difference between nuclear model and Bohr model?
Nuclear model-Positively charge nuclease at the centre surrounded negative electrons
Bohr model-Electrons orbit the nuclease at specific distances
What is an isotope?
same number of protons different number of neutrons
How did John Newland arrange the periodic table?
arranged in order of increasing atomic weights but following this created issues it meant some elements were in the wrong place
What happens when group 1 react with water?
become more reactive when going down the group
stored under oil because they react vigorously with oxygen and water
when reacted with water metal hydroxide is formed ,hydrogen gas is given off
What happens when group1 react with chlorine?
react with chlorine
lose they outer electron when reacted and form a positive ion
What are the properties of group 7?
Melting and boiling point increase when going down the group
reactivity decreases down the group
What do halogens react with?
halogens react with metals to produce an ionic salt
halogen gain an electron making it an ion with a negative charge
What bonds are formed in group 7?
form covalent compounds when they react with non-metals and ionic bonds when reacting with metals
