P3 and P4

?
explain how a gas in a sealed container exerts a pressure on the walls of the container
particles in a gas are free to move around and they collide with each other and the walls of container, this exerts a force on it, pressure is the force exerted per unit area
1 of 29
what is the formula for density? what are the units
M = pV kg/m3 or g/cm3 1g/cm3 = 1000kg/m3
2 of 29
true or false? solids are usually denser than gases
solid are generally the most dense because the particles are packed tightly together
3 of 29
describe how you could find the volume of an irregular solid object
measure its mass, submerge it in a eureka can, the water displaced by the object is transferred to the measuring cylinder, the volume of water in the cylinder is the objects volume. use formula
4 of 29
what is internal energy
the total energy that its particles have in their kinetic and potential energy stores
5 of 29
what happens to the particles in a substance when the substance is heated
heating the system transfers energy to its particles (they gain energy in their kinetic stores and move faster) increasing the internal energy
6 of 29
name the five changes of state
freezing, boiling, melting, subliming, condensing
7 of 29
true of false? the mass stays the same when a substance changes state
the mass is conserved, as you still have the original substance just in a different form
8 of 29
define specific latent heat
specific latent heat is the energy needed to to change 1kg of it from one state to another without changing the temperature E=mL
9 of 29
true of false? people used to believe that atoms were tiny sphere that couldn't be broken apart
john dalton agreed with Democritus this, but reckoned each element was made of a different type of atom
10 of 29
describe Rutherford and Marsdens experiment which disproved the plum pudding model
1909 they fired a beam of alpha particles at thin gold foil (alpha scattering experiment) most particles went through but more than expected was deflected
11 of 29
what happens to an electron in an atom if it releases EM radiation
if they gain energy by absorbing EM radiation they move to a higher energy level, further from nucleus. If realises EM they move to lower level closer to nucleus.
12 of 29
who provided evidence to suggest the existence of the neutron
Niels Bohr changed the model to have a nucleus made up of a group of particles which all had the same positive charge that added to the overall charge of the nucleus. James Chadwick proved the neutron which explained some imbalance
13 of 29
true of false? Electrons make up most of the mass of an atom
false.The nucleus is tiny but makes up most of the mass of the atom
14 of 29
what is the overall charge of an atom
it contains protons (positively charged +1) and neutrons (neutral charged 0) which gives an overall charge of positive
15 of 29
what happens to an atom if it loses one or more of its electrons
the atom will become a positively charged ion
16 of 29
what is the atomic number? what is the mass number?
Atomic number is the number of protons in an atom, mass number is the number of protons + number of neutrons
17 of 29
what is an isotope? are they usually stable?
an isotope of an element are atoms with the same atomic number but different mass number. Normally only one or two isotopes of an element are stable
18 of 29
for the three types of ionising radiation give their ionising power and range in air
ALPHA: they don't penatrate very far, only travel few cm in air and absorbed by sheet of paper. Strongly ionising. BETA: moderately ionising , few meters in air, absorbed by aluminium (5mm) GAMMA: long distances, weakly ionising, thick lead
19 of 29
Describe nuclear equations
Alpha decay decreases the charge and mass of the nucleus. Beta decay decreases the charge of the nucleus. Gamma rays don't change anything.
20 of 29
what is the activity of a source? How does activity relate to count-rate?
half-life can be used to find the rate at which a source decays -its activity. (becquerels Bq, 1Bq is 1 decay per second) Each time a radioactive nucleus decays to bocce a stable nucleus, the activity as a whole decreases.
21 of 29
define half life and describe how to find a sources half-life, given a graph of its activity over time
Half-life is the time taken for the number of radioactive nuclei in an isotope to halve. Find the time interval on the bottom axis corresponding to a halving of the activity on vertical axis.
22 of 29
define irradiation and contamination
objects near a radioactive source are irradiated by it. means they're exposed to it. If unwanted radioactive atoms get on an object its contaminated
23 of 29
give two examples of how to protect against contamination and irradiation
gloves and tongs, and protective suits (hazmat). Keeping sources in lead-lined boxes and standing behind barriers
24 of 29
complete the hazards of being irradiated and contaminated by an alpha source and a gamma source
alpha can't penetrate the skin but v dangerous in the body as in a very localised area. Beta and gamma can penetrate body and get through to organs. Beta can pass out of the body and is less damaging, gamma passes straight out - lowest ionising power
25 of 29
what is the atomic number?
atomic number is the number of protons
26 of 29
What is the mass number?
mass number is the number of protons and neutrons
27 of 29
what is transmutation
Transmutation is the name given to a process where one element changes into another.
28 of 29
Explain and compare how two different types of radioactive decay can cause transmutation.
BETA: atomic number increases by one when a neutron decays into a proton. ALPHA: Atomic number decreases by two when an alpha particle is admitted
29 of 29

Other cards in this set

Card 2

Front

what is the formula for density? what are the units

Back

M = pV kg/m3 or g/cm3 1g/cm3 = 1000kg/m3

Card 3

Front

true or false? solids are usually denser than gases

Back

Preview of the front of card 3

Card 4

Front

describe how you could find the volume of an irregular solid object

Back

Preview of the front of card 4

Card 5

Front

what is internal energy

Back

Preview of the front of card 5
View more cards

Comments

No comments have yet been made

Similar Physics resources:

See all Physics resources »See all Radioactivity resources »