The elements that belong to the third period of the periodic table are?
Li, Be, Al and P
Na, P, O and Cl
B, C, N and O
Na, Mg, S and Ar
Correct answer is D
Elements in period 3 have 3 shells in their atomic structure.
These include elements from sodium to argon.
Which of the following decrease when a given mass of gas is compressed to half its initial volume?
Atomic radius of each
Average intermolecular distance
Frequency of collisions
Number of molecules presents
Correct answer is B
No explanation has been provided for this answer.
If the electron configuration of a element is p1s2 2s2 2P5, how many unpaired electron are there?
2
8
1
4
Correct answer is C
No explanation has been provided for this answer.
How many electrons are in the L shell of 3115P?
5
8
18
2
Correct answer is B
No explanation has been provided for this answer.
What is the volume of oxygen required to burn complete 45 cm3 of methane at s.t.p?
135.0 cm3
180.0 cm3
45.0 cm3
90.0 cm3
Correct answer is D
CH4(g) + 2O2(g) → 2H2O(g) + CO2(g)
1 volume of methane will react with 90 cm3 of oxygen at s.t.p