Elements of life

Question 1

What is the mass number?

Answer 1

The number of protons plus the number of neutrons

Question 2

What is an isotope?

Answer 2

Atoms of the same element but with a different mass number because of having a different number of neutrons

Question 3

What is Mass spectrometry?

Answer 3

The measure of the atomic mass of particles (atoms or molecules)

Question 4

How does Mass spectrometry work?

Answer 4

Atoms or molecules are ionized and form cationos and are then separated based off mass and charge.

Question 5

What is nuclear Fusion? and what must happen for it to occur?

Answer 5

When two lighter nuclei are combined to make a havier nucleus of a new element.
The nuclei must come very close to each other.

Question 6

12-6-C. What do the two numbers represent?

Answer 6

The 12 is the mass.

6 is the number of protons (atomic mass)

Question 7

What happens when electrons around an atom absorb light?

Answer 7

The electrons are raised from their ground state into an excited state.

Question 8

What does the absorption spectrum look light and what does it signify?

Answer 8

It is a colored spectrum with black lines that signify what wavelengths of light have been absorbed by an atoms electrons.

Question 9

What happens after and electron moves to its excited state?

Answer 9

It will fall back to its ground state which causes a photon to be released.

Question 10

What does an emission spectrum look like? and what does it signify?

Answer 10

Black spectrum with colored lines that signify what frequency of light has been released.

Question 11

What is Bohrs theory?

Answer 11

The theory of absorption and emission spectrum. It was the first indication of electrons. It also said that energy is quantised. Also linked the behavior of light as a particle and a wave

Question 12

2 equations related to Bohrs theory:

Answer 12

Speed of light = Frequency x Wavelength

Energy of a photon = Plancks Constant x Frequency

Question 13

What is the order of subshells? and how many electrons in each?

Answer 13

S (2 electrons), P (6 electrons), D (10 electrons) , F (14 electrons)

Question 14

How do electron pairs orbit?

Answer 14

Opposite Directions

Question 15

What is the shape of the S Subshell?

Answer 15

Spherical

Question 16

What is the shape of the P Subshell?

Answer 16

Figure of 8

Question 17

Describe how electrons fill sub shells:

Answer 17

They fill from the inside out and fill each pair of electrons evenly

Question 18

Why do electron sub shells fill the way they do?

Answer 18

Because they fill up with the lowest energy configuration possible. Efficiency

Question 19

Which part of the periodic table corresponds to S, P, D?

Answer 19

S: Group 1 and 2
P: Group 3 to 8
D: Transition Metals

Question 20

How did Mendeleev arrange the periodic table? How is it arranged now?

Answer 20

Mendeleev: In order of relative atomic mass
Now: In order of number of protons

Question 21

Describe covalent bonding?

Answer 21

• Between two no-metalic atoms

- They share electrons

Question 22

Describe a dative covalent bond?

Answer 22

A covalent bond but one electron donates more electrons than the other.

Question 23

Describe the properties of a covalent bond.

Answer 23

• Very strong bond so breaking it is very hard (requires more energy)
• Electrostatic attraction between molecules is low so separating them is easily done (requires little energy)

Question 24

How are molecular shapes formed?

Answer 24

Because regions of electron density are negatively charged and so repel each other. They move as far away as possible.

Question 25

Bond angle: Linear

Answer 25

180*

Question 26

Bond angle: Trigonal planar

Answer 26

120*

Question 27

Bond angle: Tetrahedral

Answer 27

109.5*

Question 28

Bond angle: Triganal bi pyramidal

Answer 28

120* and 90*

Question 29

Bond angle: Octahedral

Answer 29

90*

Question 30

What is a mole? and what is its value?

Answer 30

A quantity of something | 6.02x10^23

Question 31

Equation for calculating the number of moles

Answer 31

Mass / Molar mass

Question 32

What is the empiracle formula?

Answer 32

The simplest molecular formula

Question 33

What is a molecular formula?

Answer 33

Condensed formula (atoms grouped together)

Question 34

Why might a yield be less than expected?

Answer 34

- Loss of reactants - Side reactions - Impurities - Temperature or pressure change - Reaction not gone to completion

Question 35

How do you calculate your yield?

Answer 35

( Experimental yield / theoretical yield ) x 100

Question 36

What is water crystallization?

Answer 36

Water molecules are trapped in the molecule of crystal. This is a hydrated crystal

Question 37

How can water composition of a hydrated crystal be calculated?

Answer 37

Heating and evaporating the water and measuring the mass change.

Question 38

What does the equation for a hydrated crystal look like?

Answer 38

CuSO4 * 5H20

Question 39

What are the properties of S block elements?

Answer 39

- Elements become more metallic as you go down the group - S block metals are weaker than other metals - They are all very reactive and so cannot be found pure

Question 40

What is first ionization enthalpy?

Answer 40

The energy required to remove and electron from the outer shell of an atom when it is in a gas state.

Question 41

What ion is formed when a gas is ionized during first ionization enthalpy?

Answer 41

Positive ion (cation)

Question 42

What is a Cation?

Answer 42

A positive ion

Question 43

What is an anion?

Answer 43

Negative ion

Question 44

What are the first ionization enthalpy trends?

Answer 44

- The energy required increase as you move across the period because there are more protons holding the electrons in place - As you move down a group the energy required gets smaller because there are more shells and more electron shielding

Question 45

What is the equation for the first and second ionization reaction with calcium?

Answer 45

Ca ==> Ca+ + e- Ca+ ==> Ca2+ + e-

Question 46

How do group 2 atoms react with oxygen?

Answer 46

They bond to make an oxide: | 2M + O2 ==> 2MO

Question 47

How do group 2 atoms react with water? and what is produced?

Answer 47

They make hydrogen | M + 2H2O ==> M(OH)2 + H2

Question 48

What happens when you heat carbonates?

Answer 48

They form an oxide and Carbon dioxide | MCO3 ==> MO + CO2

Question 49

What are the properties of thermally decomposing group 2 carbonates? and why?

Answer 49

- Harder to decompose down the group because the lower groups have a lower charge density and so form a more stable carbonate. - MgCO3 is less stable than CaCO3 so MgCO3 more readily breaks down

Question 50

How do group 2 oxides and hydroxides react with acids?

Answer 50

They form salts. e.g. MO + HCl ==> MCl2 + H2O M(OH)2 + H2SO4 ==> MSO4 + 2H2O

Question 51

Why are acids acidic?

Answer 51

Because they contain a H+ ion that dissociates in water

Question 52

Why are alkalis alkali?

Answer 52

Because they contain a OH- ion that dissociates in water.

Question 53

What happens when you combine a Acid and alkali? What is formed and how do they neutralise?

Answer 53

Acid + Alkali ==> Salt + Water H+ + OH- ==> H20

Question 54

What is a base?

Answer 54

Any substance that accepts a H+ ion

Question 55

What happens when an acid and water combine? and what is formed?

Answer 55

The water accepts the H+ ion and forms an oxonium ion. e.g. HCl + H2O ==> H3O+ + Cl-

Question 56

What is the order for sub shells?

Answer 56

1s2 2S2 2P6 3S2 3P6 4S2 3D10 4P6 4D10 4F14

Question 57

What is the relative formula mass?

Answer 57

The sum of the Relative atomic masses of atoms in a molecule

Question 58

4 equations to make ionic salts?

Answer 58

Acid + Alkali ==> Salt + Water Acid + Base ==> Salt + water Acid + carbonate == > Salt + Water + Carbon dioxide Acid + Metla ==> Salt + Hydrogen

Question 59

Describe metallic bonding?

Answer 59

Positive ions surrounded by a sea of delocalised electrons