Term 2 Flashcards
(27 cards)
Describe the plum pudding model
Sphere of positive charge with electrons embedded
What are group 0 elements called?
Noble gases
What are the properties of noble gases?
Non-metals ynteactive colourless exist as single atoms
Explain what happens to the boiling point of noble gases as you move down the group
boiling point increases
because the atoms increase in size as they have more electron shells
the intermolecular forces become stronger
so more energy is required to break these forces
What are the properties of metals
good conductor of heat and electricity shiny high density malleable and ductile
What are the properties of non metals
poor conductor of heat and electricity dull low density and brittle(break down easily)
What subatomic particles are in the nucleus of the atom
proton and neutron
what are the group one elements called
alkali metals
what are the physical properties of group 1
low melting point soft and low density
why does the reactivity of group one elements increase down the group
the number of shells increase
so the outermost elctron gets further from nucleus decreasing the forces of attraction between nucleus and outer electron
therefore easier to lose electrons
what property was used to arrange elements in early periodic table
atomic weight
Explain why lithium sodium and potassium are all in group 1 of the modern periodic table
all have one electron in outer shell so they have similar properties
number of protons electron neutrons in chlorine 35/17
P 17
E 17
N 35-17 18
what is the formula for gravitational potential energy
GPE= mass x gravitational field strength x height Ep = mgh
what is the formula for kinetic energy
KE = 0.5 x mass x Velocity squared
Ek=0.5mv(sq)
what is the formula for elastic potential
EPE = 0.5 x spring constant x extension squared l
Ee= 0.5ke(sq)
how to calculate extension
e = final length - original length
Formula for work done
work done = force x distance
formula for power
power = energy transfer/time taken
power
rate of energy transfer
define work done
measure of energy transfer
internal energy
total kinetic and potential energy of particle
specific heat capacity
energy required to raise 1 kg of the material by 1 degrees celsius
fórmula for specific heat capatuity
thermal energy= mass x shc x change in t
