Answer:
Potassium
1s2 2s2 2p6 3s2 3p6 4s1
Explanation:
The atom having only one electron its outermost shell must belong to an element in group one of the periodic table.
Having noted that, we proceed to find out what element in group one that has the atom just described in the question.
That atom must belong to an element in the fourth period. The only group 1 element in the fourth period is potassium.
The electron configuration of potassium is;
1s2 2s2 2p6 3s2 3p6 4s1
Answer:
Work done, W = 128 kJ
Explanation:
Given that,
Weight of a mountain climber, F = 800 N
It climbs to a cliff that is 160 m high.
We need to find the work done by the mountain climber. The work done by an object is given by the formula as follows :
W = Fd
Put the values of F and d.
W = 800 N × 160 m
W = 128000 J
or
W = 128 kJ
So, 128 kJ of work is done by the mountain climber.
Answer:
c. Cr
Explanation:

The compound is containing
ion.
If acid reacts with it, CO_2 evolves.

therefore, Cr would form a precipitate when added to an aqueous solution of this compound. Cr2CO3 is the precipitate.