The one in the middle since when ur going down it’s more quicker anc faster .
Halogen--Florine
Chalogen-- Oxygen
Alkali Metal-- Sodium
Boron -- Metalloid (atomic symbol B)
Lanthanide series-- (Number 57-71 on periodic Table) Example: Cerium #58
Alkaline Earth Metal--Magnesium
Transition Metal-- Gold, Iron, Silver. Etc... (Middle section of a period table)
Nobel Gas--Helium
The red sign pops up on the side of the bus.
Answer:
8
Explanation:
there are two ammonium ions with four hydrogen atoms each.
4*2=8
Answer:
A - 3
B - 6
Explanation:
The valency of hydrogen atom is +1
The valancy of an atom of other element combining with the hydrogen atom can be determined from the number of associated hydrogen.
when H combines with A, three atoms of hydrogen are used. Thus the valency of element A is -3
Now B combines with two molecules of A whose valency is -3
The valency of B would be twice the valency of element A i.e 6
if hydrogen combines with B, then the compound formed will be BH6
