1.1 Basic ideas about atoms, first half
0.0 / 5
- Created by: Danielle
- Created on: 03-12-13 18:51
What is an atomic number?
the number of protons in the nucleus of an atom
1 of 53
What is an ion?
a particle where the number of electrons does not equal the number of protons
2 of 53
What is an isoptope?
atoms having the same number of protons but different number of neutrons
3 of 53
What is a mass number?
the number of protons plus the number of neutrons in the nucleus of an atom
4 of 53
What is the mass of an electron?
1/1840 or negligible
5 of 53
What is a cation?
A positive ion
6 of 53
What is an anion?
A negative ion
7 of 53
*1 Bromine had two naturally occurring isotopes. 79,35 Br and 81,35 Br. Give the number of protons, neutrons and electrons in each isotope.
35 - p 35 - e 44- n and 35 - p 35 - e 46 - n
8 of 53
*2 State the number of protons and electrons in both Na+ and F-
Na+ - 11p 10e F- - 9p 10e
9 of 53
What is an alpha particle?
A cluster of 2 protons and 2 neutrons
10 of 53
Does an alpha particle have a charge?
Yes, it has a positive charge
11 of 53
What is the penetrating power of an alpha particle?
Can be stopped by a piece of paper
12 of 53
How does the emission of an alpha particle affect the mass and atomic number?
The mass number decreases by 4 and the atomic number decreases by 2
13 of 53
What is a beta particle?
A fast moving electron
14 of 53
Does a beta particle have a charge?
Yes, it is negative
15 of 53
What is the penetrating power of a beta particle?
Can be stopped by a **** of thin metal for example 0.5 cm of aluminium
16 of 53
How does beta emission effect the mass and atomic number of the atom?
The mass number is unchanged and the atomic number increases by 1
17 of 53
What is a gamma ray?
A high energy electromagnetic radiation
18 of 53
Does a gamma ray have a charge?
No, it is uncharged
19 of 53
What effect does gamma ray have on the mass and atomic number of the atom?
There is no change
20 of 53
What is the penetration power of gamma rays?
Can take more than 2 cm of lead to stop
21 of 53
*3 Why are victims of radioactive contamination buried in lead coffins?
Radioactive emissions are stopped by a lead shield thus preventing escape of the radioactivity
22 of 53
*4 Give the mass number and symbol of the isotope formed when 211 Bi decays by alpha emission
207 Ti
23 of 53
What is a half-life?
The time taken for half the atoms in a radioisotope to decay or the time taken for the radioactivity of a radioisotope to fall to half of its initial value.
24 of 53
Why are radio emissions dangerous?
As high energy radioactive emissions can break cell bonds within molecules causing changed in DNA causing mutation at low doses and death at high doses
25 of 53
*5 Outline why radioactivity may be a health hazard.
Radiation is ionising/releases high energy/produces radicals/breaks chemical bonds/causes cell mutation. This causes burns/sickness/cancer
26 of 53
*6 An isotope of iodine 131-I has a halflife of 8 days. How long would it take for 1g to be reduced to 0.125g of 131-I.
24 days
27 of 53
*7 Radioactive iodine 131-I is used in medicine as a tracer. Give another use of radioactive isotopes apart from in medicine.
Carbon-14 used in radiodating/alpha emitters in smoke alarms/beta emitters to regulate the thickness of metal foil
28 of 53
What radioactive isotope is used in radiotherapy for the treatment of cancer?
Cobalt-60
29 of 53
What is the isotope that emits gamma rays Cobalt-60 used in?
Medicine - radiotherapy, treatment of cancer
30 of 53
What is the radioactive isotope used in radio dating?
Carbon-14
31 of 53
What is the radioactive isotope carbon-14 used in?
Radio-dating - calculate the age of plant and animal remains
32 of 53
What is an atomic orbital?
A region in an atom that can hold up to two electrons with opposite spins
33 of 53
How many electrons can a s sub shell hold?
2
34 of 53
How many electrons can a p sub shell hold?
6
35 of 53
How many electrons can a d sub shell hold?
10
36 of 53
What shape is an s orbital?
spherical
37 of 53
What shape is a p orbital?
dumbbell shape
38 of 53
How are atoms clssified into the 'blocks'?
The last electron in either the s, d, p or f shell
39 of 53
Define electronic configuration
The arrangement of electrons in an atom
40 of 53
What two atoms have slightly different electronic configurations, both end in 4s1
Chronium and copper
41 of 53
What is the filling order for electronic configuration?
1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s
42 of 53
What is the electronic configuration of Na?
1s2, 2s2, 2p6, 3s1
43 of 53
What is electron shielding or screening?
The repulsion between electrons in different shells, inner shell electrons repel outer shell electrons
44 of 53
What is molar first ionisation energy of an element?
The energy required to remove one mole of electrons from one mole of its gaseous atoms
45 of 53
*9 State and explain the general trend in ionisation energy. (a) across a period (b) down a group
(a) increase, because nuclear charge increases steadily but there is not much change in shielding (b) Decrease, because outer electron has increased shielding from inner electrons and it is further from the nucleus
46 of 53
What three factors affect the attraction between the electrons and there nucleus?
1 - Nuclear charge; bigger the charge the bigger the attraction 2 - Electron shielding;the more sheilding the less the attraction 3 - The atomic radius;the greater the smaller the attractive force
47 of 53
He has a greater ionisation energy than Ne because...
neons outer electrons has increased shielding and is further from the nucleus
48 of 53
He has a greater ionisation energy than Li because...
lithiums outer electron is in a new shell which has increased sheilding and is further from the nucleus
49 of 53
Ne has a greater ionisation energy than O because...
as the effect of the nuclear charge is greater but in the same sub shell so only a little extra sheliding
50 of 53
Be has a greater ionisation energy than B because...
as borons outer electron is in a new sub shell so is further from the nucleus and is shielded from 2s electrons
51 of 53
N has a greater ionisation energy than O because...
the electron-electron repulsion between the two paired electrons in one p oribital makes it harder to remove an electron, nitrogen has no paired electrons
52 of 53
*10 Write an equation to represent the second ionisation energy of magnesium.
Mg+ (g) -> Mg2+ (g) + e-
53 of 53
Other cards in this set
Card 2
Front
What is an ion?
Back
a particle where the number of electrons does not equal the number of protons
Card 3
Front
What is an isoptope?
Back
Card 4
Front
What is a mass number?
Back
Card 5
Front
What is the mass of an electron?
Back
Related discussions on The Student Room
Similar Chemistry resources:
0.0 / 5
0.0 / 5
0.0 / 5
0.0 / 5
5.0 / 5 based on 1 rating
4.0 / 5 based on 1 rating
0.0 / 5
Comments
No comments have yet been made