Elements in the same group of the periodic table have
the same number of valence electrons
the same number of electron shells
different chemical behaviour
the same atomic size
Correct answer is A
No explanation has been provided for this answer.
Which of the following statements is not true of halogens?
they exist in different physical states
they exist as diatomic molecules
their ionic radii decrease down the group
their melting and bolling points increase down the group
Correct answer is C
No explanation has been provided for this answer.
86 and 230
87 and 234
88 and 233
90 and 238
Correct answer is A
\(^{234} _{88} Q \to R + ^4 _2 He\)
\(\therefore R = ^{234 - 4} _{88 - 2} R\)
= \(^{230} _{86} R\)
What is the atomic number of an element whose cation Y+ has the electronic configuration 1s22s22p6?
9
10
11
12
Correct answer is C
No explanation has been provided for this answer.
The valence electrons in a chloride ion are [17CI]
2p electrons only
3s and 3p electrons only
3p and 3d electrons only
3p electrons only
Correct answer is B
No explanation has been provided for this answer.