Question

Element P has 5 electrons in its L shell while element Q has5 electrons in its M shell. which of the following statements is correct regarding elements P and Q?
a)both elements have valency equals 5
b)both elements have the same mass number
c)atomic number of element p is 7 and that of q is 15
d)both elements show valency equal to 3 only.

Answer 1

Answer:

Both c and d are correct!!!!!!!¡

Answer 2

P has 5 electrons in its L shell

Q has 5 electrons in its M shell

so the electronic configuration will be as :

For P- 2, 5

For Q- 2, 8,5

___________________________

a) what element has valency equal to 5

The answer is no after 4 we start subtracting the valency, so we can say that the valency of the element will be 8 - 5 = 3. The statement is wrong for P and Q.

b) what element will have same mass number

The number of protons and the number of neutrons determine an element's mass number: mass number = protons + neutrons. If you want to calculate how many neutrons an atom has, you can simply subtract the number of protons, or atomic number, from the mass number.

c) atomic number of P is 7 and Q is 15.

The number of electrons is equal to atomic number which is true.

d) both elements show valency equal to 3 only.

Its wrong as we can see it's not happening.

________________________

so the correct answer is C