Periodic Table

Question 1

who came up with the first idea of elements

Answer 1

greeks
fire water air earth

Question 2

Who came up with the first definition of an element
-irish

Answer 2

Robert Boyle

Question 3

an element is

Answer 3

a substance that cannot be broken into simpler substances by chemical means

Question 4

Who discovered a load of elements and how

Answer 4

Humphrey davy
passed electricity through compounds
discovered potassium, calcium, sodium, magnesium

Question 5

Dobereiner

Answer 5

Arranged known elements in order of of increasing atomic weight
noticed the weight of the middle element in a group of 3 was half of the other 2

Question 6

group of 3 in the periodic table

Answer 6

triad

Question 7

why was dobereiners triads ignored

Answer 7

only 4 examples
coincidence

Question 8

why is dobereiner important

Answer 8

earliest attempt at a pattern in the periodic table

Question 9

example of a triad

Answer 9

Cl, Br, I

Ca, St, Ba

Question 10

what is a triad

Answer 10

a group of 3 elements with similar chemical properties in which the atomic weight of the middle element is equal to the average of the other two elements

Question 11

what did newlands do

Answer 11

arranged the known elements in order of increasing atomic weight
noticed every 8th element had similar properties to the first (law of octaves)

Question 12

what are the problems with newlands law of octaves

Answer 12

not all elements resembled each other in the groups they were placed in

he should have left space for undiscovered elements

noble gases were not yet discovered due to their unreactivity

Question 13

Newlands octaves

Answer 13

arrangements of elements in which the 1st and 8th elements when counting from a particular element have similar properties

Question 14

what is the similarity between the modern periodic table and newlands

Answer 14

every 9th element has similar properties to the first
newland had not left space for undiscovered elements
grou[p 8 had not yet been discovered

Question 15

how did Dmitri Mendeleev figure out the periodic table

Answer 15

wrote all known elements on cards
organised them in order of increasing atomic weight

Question 16

how did dmitri mendeleevs periodic table differ from those before

Answer 16

he left space for undiscovered elements
he did not force elements into groups if they did not share similar properties
tellurium placed iodine before tellurium

Question 17

diferences between mendeleevs periodic table and the modern table

Answer 17

Mendeleev arranged elements in order of increasing atomic weight
currently arranged in order of increasing atomic number

he left gaps for undiscovered elements
no gaps

noble gases were not yet discovered
group 8

63 elements
118 elements

transition metals were included in groups
seperate block for transition metals

Question 18

Importance of tellurium and iodine

Answer 18

Mendeleev placed iodine before tellurium despite tellurium having a bigger atomic mass so that each element shared properties of the group it was placed in

Question 19

Henry mosely

Answer 19

measured the number of protons in the nuclei of atoms (atomic number)

Question 20

who discovered the atomic number of elements

Answer 20

Henry mosely

Question 21

how did Henry mostly contribute to mendeleevs periodic table

Answer 21

proof that tellurium should be placed before iodine due to their atomic number

Question 22

relative atomic mass defintion

Answer 22

the average of the mass numbers of the isotopes of the element

as they occur naturally

taking their abundances into account
expressed on a scale in which the atoms of the carbon-12 isotope have a mass of exactly 12 units

Question 23

what is a mass spectrometer used for and how

Answer 23

to identity isotopes of elements
measures their % abundance

Question 23

steps of mass spectrometry in order

Answer 23

Vaporisation
ionisation
Acceleration
Seperation
Detection

Question 24

uses of a mass spec

Answer 24

Forensic science - testing confiscated drugs Tested banned substances in athletes (blood or urine) space technology (analysed Haileys comets tail)

Question 25

why is the mass number of an element usually not a whole number

Answer 25

atoms of the same element with the same atomic number but can have different masse due to the different number of neutrons in their nuclei

Question 26

what happens during vaporisation

Answer 26

Small amount of a gas or liquid is injected through the sample inlet

Question 27

how would a solid be put into a mass spec

Answer 27

furnace attachment

Question 28

what happens during ionisation

Answer 28

an electron gun fired high energy electrons at atoms electrons are lost from atoms leaves behind positively charged ions

Question 29

what happens during acceleration

Answer 29

negatively charged plates attract the positively charged ions and they're accelerated at high speeds

Question 30

what happens during seperation

Answer 30

A single beam of positive ions are operated into 2 or more beams according to their mass Lighter particles are easier to deflect and can be pushed off course Heavier particles are more difficult to detect and are sent to the deflector

Question 31

what happens during detection

Answer 31

sensitive instrument can detect particles that hit it it counts the number of particles that hit it with a specific mass by adjusting the magnetic field, particles with different masses can be detected

Question 32

Mendeleevs periodic law

Answer 32

elements arranged in order of increasing atomic mass the properties of the elements repeat periodically in columns of similar chemical properties

Question 33

Moseleys periodic law (modern)

Answer 33

Elements arranged in order of increasing atomic number the properties of the elements repeat periodically

Question 34

Relative Atomic Mass (ram)

Answer 34

the average mass number of the isotopes of an element as they occur naturally taking their abundances into account relative to the mass of the carbon-12 isotope

Question 35

valency

Answer 35

the number of hydrogen atoms or other monovalent element with which each atom of the element combines

Question 36

sigma bond

Answer 36

formed by the head on overlap of atomic orbitals

Question 37

pi bond

Answer 37

formed by the sideways overlap of p d and f orbitals