the periodic table Flashcards
1
Q
what is ‘mr’
A
its the molecular mass of a compound
2
Q
what is in the central region of an atom
A
nucleus
3
Q
what are the 3 subtonic particles
A
protons
neutrons
electrons
4
Q
max amount of electrons each shell can hold
A
1st shell - 2 electrons
2nd shell - 8 electrons
3rd shell - 8 electrons
5
Q
why did Mendeleev leave spaces in the periodic table
A
the elements still wernt discovered and he predicted where the elements would go
