Chemistry
The element 'X' has same number of protons, neutrons & electrons, with same number of electrons in 'K' shell & 'N' shell. The element -
- Is a non-metal with valency -2.
- Attains stable octet structure of the nearest inert gas 'Ar', by gain of two electrons in its valence shell.
- Is a metal with valency +2.
- X2+ has electronic configuration 2, 8.
Answer
Is a metal with valency +2.
Reason — The element X has same number of protons, neutrons, and electrons.
K shell can contain only 2 electrons, so N shell also has 2 electrons. So, the electronic configuration is 2, 8, 8, 2
Total electrons = atomic number = 20
Since, there are 2 electrons in the outermost shell. The element can lose 2 electrons to attain stability. After losing 2 electrons, it will gain the valency of +2.
Thus, we can say it's a metal with valency +2.
Related Questions
Which of the following is correct in an element AZY.
- Number of neutrons = Z-A
- Number of protons = A
- Z = sum of protons & electrons
- A = sum of neutrons & electrons
Assertion: Elements 11H, 21H, 31H have different number of neutrons.
Reason: Isotopes have the same atomic number.
- Both A and R are true and R is the correct explanation of A.
- Both A and R are true and R is not the correct explanation of A.
- A is true and R is false.
- A is false and R is true.
Elements 2010X & 4018Y
- Are highly reactive.
- Both have 8 electrons in 'M' shell.
- Are isotopes of the same element.
- Do not gain, lose or share electrons.
Four elements A, B, C, D are given :
A shows the presence of 20 neutrons, 17 protons and 17 electrons.
B shows the presence of 18 neutrons, 17 protons and 17 electrons.
C shows the presence of 10 neutrons, 9 protons and 10 electrons.
D shows the presence of 4 neutrons, 3 protons and 2 electrons.
State which of the above is —
(a) an anion
(b) a cation
(c) a pair of isotopes.
Write the formula of the compound formed between D and C.