Answer:
The reason that that elements in the same 'group' have similar chemical properties is because they have the same number of valence electrons. ... Iron when reacting in chemical reactions loses electrons from its 4s orbital instead of its d orbital
Nuclear fission because an atom is splitting in two fragments.
(a) distance measured with metre rule or tape rule
time measured with stopwatch/ stop clock/ timer
Average speed = total distance / time
(b) (i) decrease in speed
(ii) Change in speed = a * t
4.5 m/s
<em>hope this helps......</em>
Isotopes are elements with the same number of protons but different number of neutrons
1) period
2) the answer is D) I because they are in the same column
3) B)Ge because they are in the same column
4) A) Al because they are in the same column (share same characteristics)
5) D) they have the same number of valence electrons
6) D) nonmetals