2- Atoms, Ions and Compounds

Question 1

what is the abbreviation of a proton?

Answer 1

p+

Question 2

what is the abbreviation of a neutron?

Answer 2

n

Question 3

what is the abbreviation of a electron?

Answer 3

e-

Question 4

What is the relative charge of a proton?

Answer 4

+1

Question 5

What is the relative charge of a neutron?

Answer 5

0

Question 6

What is the relative charge of a electron?

Answer 6

1-

Question 7

What is the relative mass of a proton?

Answer 7

1

Question 8

What is the relative mass of a neutron?

Answer 8

1

Question 9

What is the relative mass of a electron?

Answer 9

1/1836

Question 10

What subatomic particles are present in the nucleus?

Answer 10

Protons and neutrons

Question 11

Why are neutrons in the nucleus?

Answer 11

To overcome the electrostatic repulsion of the protons in the nucleus. Otherwise protons would break apart. Neutrons act like glue that holds the nucleus together

Question 12

When does an atom become radioactive?

Answer 12

When there are not enough neutrons to overcome electrostatic force, not stable to maintain, protons split apart

Question 13

What is the overall charge of an atom?

Answer 13

Zero. Total positive charge from protons is balanced out by the total negative charge of electrons

Question 14

What is the atomic number equal to?

Answer 14

Proton number

Question 15

Where are electrons found?

Answer 15

energy levels

Question 16

What is an isotope?

Answer 16

Atoms of the same element with a different number of neutrons and a different masses

Question 17

Do isotopes of the same element have the same chemical properties?

Answer 17

Yes, all have the same number of electrons. neutron number has no effect on reactions of element. ASll isotopes of a element react in the same way

Question 18

Do isotopes of the same element have the same physical properties?

Answer 18

No, different neutron number so different physical properties

Question 19

How do you work out the mass number?

Answer 19

Number of protons + number of neutrons

Question 20

How do you work out the number of neutrons?

Answer 20

Mass number - Atomic (proton) number

Question 21

What is an ion?

Answer 21

A charged atom. The number of electrons is different from the number of protons

Question 22

What is a positive ion called?

Answer 22

Cation
-fewer electrons then protons

Question 23

What is a negative ion called?

Answer 23

Anion
-more electrons then protons

Question 24

What is relative isotopic mass?

Answer 24

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

Question 25

What is the mass of a carbon-12 isotope?

Answer 25

1.992646538 x 10^-26 kg

• 12 atomic mass units (12u)
• 1u = 1/12th of an atom of carbon-12
  -1u = approx the mass of a proton or neutron

Question 26

What is relative atomic mass?

Answer 26

The weighted mean mass of an atom of an element relative to 1/12th the mass of an atom of Carbon-12

Question 27

What does the weighted mean mass take into account?

Answer 27

-percentage abundance of each isotope
-relative isotopic mass of each isotope

Question 28

What is mass defect?

Answer 28

The difference between the actual mass of an atom and the sum of the masses of its protons, neutrons and electrons.

The missing mass is the binding energy holding the atom together

Question 29

How do you work out the percentage abundances of the isotopes in a sample of an element?

Answer 29

mass spectroscopy

Question 30

How does the mass spectrometer work?

Answer 30

1. The same is placed into the mass spectrometer
2. The sample is vaporised and turned into a gas
3. Sample is ionised to form positive ions
4. Ions are accelerated. heavier ions move slower and are more difficult to deflect then lighter ions, so ions of each isotope are separated
5. Ions are detected on a mass spectrum as a mass-to-charge ratio m/z. Each ion reaching the detector adds to the signal, so the greater the abundance, the larger the signal

Question 31

How do you work out the mass-to-charge ratio (m/z)?

Answer 31

m/z = relative mass of ion / relative charge of ion

Question 32

What is a binary compound?

Answer 32

An compound that is made of two elements only

Question 33

How do you work out the name of a binary compound?

Answer 33

-use the name of the first element but charge the ending of the second element to -ide
-for ionic compounds, metal ion always comes first

Question 34

What is the charge of Ag ions?

Answer 34

1+

Question 35

What is the charge of Zinc ions?

Answer 35

2+

Question 36

What are polyatomic ions?

Answer 36

Ion formed of mor then 1 atom bonded together with an overall charge

Question 37

What are the formula and charge of nitrate?

Answer 37

NO3-

Question 38

What are the formula and charge of carbonate?

Answer 38

CO3 2-

Question 39

What are the formula and charge of sulfate?

Answer 39

SO4 2-

Question 40

What are the formula and charge of hydroxide?

Answer 40

OH-

Question 41

What are the formula and charge of ammonium?

Answer 41

NH4+

Question 42

What are the formula and charge of nitrite?

Answer 42

NO2-

Question 43

What are the formula and charge of hydrogencarbonate ?

Answer 43

HCO3-

Question 44

What are the formula and charge of manganate(VII)?

Answer 44

MnO4 -

Question 45

What are the formula and charge of sulfite?

Answer 45

SO3 2-

Question 46

What are the formula and charge of dichromate(VI)?

Answer 46

Cr2O7 2-

Question 47

What are the formula and charge of phosphate?

Answer 47

PO4 3-

Question 48

What are the naming rules?

Answer 48

-numbers in subscript
-ion charges not in final formula as compound is neutral
-brackets used for polyatomic ions

Question 49

What are the rules when balancing equations?

Answer 49

-not change any of the chemical formula
-balancing numbers go in front of the chemical formulae and on the line
-the same amount of atoms of each element on each side of equation

Question 50

What are diatomic molecules? And which are they?

Answer 50

Two atoms bonded together

H2 N2 O2 F2 Cl2 Br2 I2
P4 S8