C1 - atomic structure Flashcards
the periodic table is arranged by…
atomic/proton number
what never changes about an element?
number of protons
how did Mendeleev rearrange the periodic table?
he reversed the order of some elements so they fitted in groups of reactivity
why did Mendeleev leave gaps in the periodic table?
he realised some elements were still undiscovered
how was Mendeleev’s table arranged?
in order of protons, not mass
number of protons = ?
atomic number
number of neutrons = ?
mass number minus atomic number
number of electrons = ?
number of protons
how are electrons arranged?
in shells
how many electrons can the 4th shell hold?
2
what does the group number tell us about the electrons?
number of electrons an element has in the outer shell
where are protons and neutrons located?
in the nucleus
where are electrons located?
in shells orbiting the nucleus
describe the plum pudding model
ball of positive charge with negative electrons embedded throughout
what did Rutherford suggest about electrons to prove the nuclear model incorrect?
they orbit the nucleus
how did Bohr develop the nuclear model further?
he suggested electrons were in shells orbiting a nucleus of protons
name a similarity between the plum pudding model and the nuclear model
both have negative and positive charges
what did James Chadwick discover in 1932?
neutrons