periodic table (topic 1) Flashcards
what is the modern name for atomic weight
relative atomic mass
atomic
comparative points (max 2 marks):
- both tables have more than one element in a box
- both have similar elements in the same column
- both are missing the noble gases
- both arranged elements in order of atomic weight
advantages of mendeleevs /disadvantages of newlands periodic table (max 2 marks):
- newlands did not leave gaps for undiscovered elements
- newlands had many more dissimilar elements in a column
- mendeleev left gaps for undiscovered elements
- mendeleev changed the order of some elements (e.g. Te and I)
points which led to the acceptance of mendeleevs table (max 2 marks)
- mendeleev predicted properties of missing elements
- elements with properties predicted by mendeleev were discovered
- mendeleevs predictions turned out to be correct
- elements were discovered which fitted the gaps
mendeleev
name two elements in group 1 of this periodic table which are not found in group 1 of the modern periodic table
- hydrogen
- copper
- silver
which group of elements in the modern periodic table is missing on mendeleevs table
noble gases
give one reason why the mendeleev left gaps in this periodic table
- for elements that had not been discovered (at that time)
- so that elements with similar properties are grouped together
describe two links between atomic structure and the periodic table (2)
- elements arranged in atomic number order
- elements in same group have same number of outer electrons
- elements in same period have same number of electron shells
- number of electron shells increases down each group
in what group are alkali metals
group 1
in what groups are the transition metals
central block
in what group are the halogens
group 7 (one from right end next to 0)
in what group are the noble gases
0
mendeleev knew that there must be undiscovered elements, how did he take this into account when he designed his periodic table (2)
- mendeleev left gaps
- if placed consecutively, elements would be in wrong group (have wrong properties or some elements didnt fit pattern)
by the early 20th century protons and electrons had been discovered, describe how this discovery allowed chemists to place elements in their correct order (3)
- elements placed in atomic number order
- elements in the same group have same number of outer electrons
- number of protons = number of electrons
- chemical properties depend on the outer electrons
- number of shells gives the period
- transition metals are harder than Group 1 metals
- transition metals have higher melting points than Group 1 metals
- transition metals often form coloured compounds but Group 1 compounds are usually white
- conducts heat
- forms coloured compounds
- high melting point
- strong
- they form ions with different charges
- they have high melting points
- has a higher melting point
- is harder
plan:
- add the metals to dilute hydrochloric acid
- measure temperature change (or compare rate of bubbling or compare colour of resulting solution)
observations for copper:
- no reaction
- shown by no temperature change (or shown by no bubbles)
observations for magnesium and iron:
- magnesium has a higher increase in temperature than iron (or magnesium bubbles faster than iron or magnesium forms a colourless solution AND iron forms a coloured solution)
control variables (max 2 marks):
- same concentration of hydrochloric acid
- same volume of hydrochloric acid
- same mass of metal
- same particle size of metal
- same temperature of acid if comparing rate of bubbling
metals:
- can be hammered into shape, good conductor of electricity, shiny
non-metals:
- brittle, dull, poor conductors of electricity
(1)
they have the same number of outer electrons
