2 Atomic

Question 1

how to calculate relative atomic mass?

Answer 1

sum of (isotope mass • isotope abundance)/sum of (isotope abundance)

Question 2

why do elements have DISCRETE line spectra?

Answer 2

each element’s electrons only move between FIXED ENERGY LEVELS

Question 3

what does EACH COLORED LINE on the spectra show?

Answer 3

transition of electron between energy levels

Question 4

energy level further from nucleus = ? energy

Answer 4

higher energy

Question 5

lines in the UV region shows

Answer 5

electron transitions to n1

Question 6

lines in the VISIBLE region shows

Answer 6

electron transitions to n2

Question 7

draw a line spectra

Answer 7

-

Question 8

Atomic number = ?
Mass number = ?

Answer 8

Atomic number = p = e
Mass number = p + n

Question 9

define isotope

Answer 9

same proton number,
different neutron number

Question 10

what happens to the physical & chemical properties to isotopes?

Answer 10

• same chemical property - same number of outer electrons
• different physical property - different number of neutrons = different mass

Question 11

whats the difference between ifference between continuous and line spectrum?

Answer 11

Continuous spectrum has all wavelengths;

Line spectrum has only a few wavelengths

Question 12

the spetra lines converge at?

Answer 12

higher energy
= higher frequency
= shorter wavelength

Question 13

Emission Line Spectra
* When is it produced?
* What are its characteristics?
* Draw the emission line spectra of hydrogen

Answer 13

• Electrons emit energy+ transition to lower energy levels.
• black background + discrete colored lines
• Converge as frequency increase

Question 14

Absorption Line Spectra
* When is it produced?
* What are its characteristics?
* Draw the absoprtionline spectra of hydrogen

Answer 14

• Electrons absorb energy+ transition to higher energy levels.
• rainbow background + black lines
• Converge as frequency increase

Question 15

How many electrons can each sublevel hold?

Answer 15

Electrons are arranged in energy levels, which have sub-levels. Each sub-level consists of orbitals and each orgbital can hold 2 electrons.
* s → 2x1 = 2 electrons
* p → 2x3 = 6 electrons
* d → 2x5 = 10 electrons

Question 16

Electrons in the same orbital spin in

Answer 16

opposite directions

Question 17

Electrons start from filling

Answer 17

the lowest energy level
* UNOCCUPIED → [s] has lower energy than [d] → electrons fill [s] before [d]
eg. Fe (26e-) → 1s2 2s2 2p6 3s2 3p6 3d64s2
* OCCUPIED → electrons are removed from [s] before [d] to form ions!
eg. Fe2+ (24e-) → 1s2 2s2 2p6 3s2 3p6 3d6

Question 18

For the same energy level, electrons fill orbitals

Answer 18

singly first,
then pair

Question 19

electron configuration for Cr

Answer 19

[Ar] 3d⁵ 4s¹

Question 20

electron configuration for Cu

Answer 20

[Ar] 3d¹⁰ 4s¹