sc4, the periodic table (paper 1 and 2) Flashcards
1
Q
how did mendeleev order the periodic table
A
- increasing relative atomic mass
- he kept missing gaps in the table
- sometimes swapped elements for better suited chemical properties
2
Q
why did mendeleev leave gaps in his table
A
- some chemical and physical properties didnt line up with the increasing relative atomic mass
- so he thought other elemetns were to be discovered
- he guessed their properties
3
Q
give reasons for why early scientists didn’t believe in mendeleevs table
A
- there were gaps
- hydrogen wasn’t properly placed
4
Q
how did mosely show RAM was a physical property
A
- he fires high energy electrons at different elements
- which gave off x rays
- every step increase in atomic number, there was a step change in the energy of these x rays
5
Q
explain how ordering by relative atomic masses could be wrong
A
becuz of isotopes