Atoms, Isotopes and Equations Flashcards Preview

Chemistry AS > Atoms, Isotopes and Equations > Flashcards

Flashcards in Atoms, Isotopes and Equations Deck (41):
1

What are the three main subatomic particles in an atom?

Proton, Neutron and electron

2

Where is the proton found?

In the nucleus

3

What is the relative charge and mass of a proton?

Charge: 1+
Mass: 1

4

Where is a neutron found?

In the nucleus

5

What is the relative charge and mass of a neutron?

Charge: 0
Mass: 1

6

Where is an electron found?

In the energy levels/ shells around the nucleus

7

What is the relative charge and mass of an electron?

Charge: 1-
Mass: 1/1836

8

What is the definition for Atomic number (z)?

The number of protons in the nucleus and identifies an element

9

What is the definition for Mass number (A)?

Number of protons and neutrons in the nucleus

10

How can you calculate the number of neutrons?

N= mass number - atomic number

11

What is the number of electrons equal to?

The number of protons

12

What is the definition for an Ion?

Positively or negatively charged atoms/ group of atoms where the number of electrons is different from the number of protons

13

When is an ion formed?

When an atom gains or looses electrons

14

What is a cation?

A positive ion

15

What is a anion?

A negative ion

16

What is the definition for an isotope?

Atoms of the same element with the same number of protons and electrons, but different numbers of neutrons.

17

Why do isotopes have the same chemical properties?

Chemical reactions involves electrons, so isotopes of an element have the same chemical properties as they have the same number and arrangement of electrons.

18

What is the definition for relative mass?

As atoms are so small chemists use relative atomic masses to compare the masses of atoms, elements an compounds

19

What is the standard measurement of relative masses and why is it used?

Carbon-12, 12C is used as the standard measurement of relative masses, as 1/12th of 12C is essentially the mass of a proton/ neutron.

20

What is the definition for Relative isotopic mass?

Mass of an atom of an isotope relative to 1/12th of the mass of an atom of carbon-12

21

What is the definition for Relative atomic mass, Ar?

Weighted mean mass of an atom of an element relative to 1/12th of the mass of an atom of carbon-12

22

What is a mass spectrometer used for?

A mass spectrometer can be used to identify isotopes and their abundances, which can then be used to calculate relative atomic mass

23

What are the 5 steps to mass spectrometry?

1. The sample is VAPOURISED, then IONISED to cations.
2. Ions are ACCELERATED to EQUAL KINETIC ENERGY so the heavier ions move more slowly towards the detector.
3. Ions create a signal at the detector, the MORE ABUNDANT ions create a BIGGER signal.
4. Lighter ions meet the detector first
5. A computer converter turns the ELECTRICAL signals into a MASS SPECTRUM.

24

What is the equation for calculating Relative atomic mass from mass spectrometry?

Ar= Sum(Isotopic mass X abundance) / Total Abundance

25

How many decimal places is Relative atomic mass quoted to?

1 d.p

26

What is chemical formulae used for?

To tell you the ratio of elements present in a compound

27

What are the 7 diatomic elements?

H2, N2, 02, F2, CL2, BR2, I2

28

What are the two element exceptions for structure?

P4 and S8

29

When is a ionic compound created?

METAL+ NONMETAL

30

When is a covalent compound created?

NONMETAL + NONMETAL

31

What are binary compounds?

Compounds containing only two elements

32

What is the element number up to Group 7?

Group 1 = 1+
Group 2 = 2+
Group 3 = 3+
Group 5 = 3-
Group 6 = 2-
Group 7 = 1-

33

What are polyatomic ions?

Groups of atoms covalently bonded together, they have gained or lost electrons, forming negative or positive ions respectively.

34

What are the first four prefix's for covalent compounds?

1. mono-
2. di-
3. tri-
4. tetra-

35

What is an ionic equation?

Show which ions actually react and leave out ions that remain unchanged, in aqueous solutions before and after the reaction.

36

What is the chemical equation for ammonia?

NH3

37

What is the chemical equation for methane?

CH4

38

What is the chemical equation for water?

H2O

39

What is the chemical equation for hydrogen sulphide?

H2S

40

What is the chemical equation for propane?

C3H8

41

What is the chemical equation for ethane?

C2H6