The total number of neutrons in dipositive zinc ions with mass number 70 is -
1. 34
2. 40
3. 36
4. 38
An atom forms an ion by losing three electrons. The ion has an electronic configuration [Ar]3d6. The symbol of the ion is :
1. | Fe3+ | 2. | Ni3+ |
3. | Co3+ | 4. | Mn+3 |
The number of electrons in one molecule of CO2 are -
1. 22
2. 44
3. 66
4. 88
The ion that is isoelectronic with CO is-
1. CN-
2. O2+
3. O2-
4. N2+
The number of electrons in the valence shell of calcium is
1. 6
2. 8
3. 2
4. 4
Which of the following has the maximum number of unpaired electons-
1. Mg2+
2. Ti3+
3. V3+
4. Fe2+
The number of d- electrons retained in Fe2+ :
1. 5
2. 6
3. 3
4. 4
An isotone of 32Ge76 is:
(i) 32Ge77
(ii) 33As77
(iii) 34Se77
(iv) 34Se78
1. only (i) & (ii)
2. only (ii) & (iii)
3. only (ii) & (iv)
4. (ii) (iii) & (iv)
Which of the following has greater number of electrons than neutrons?
1. Al3+
2. O2-
3. F-
4. C
The number of electrons in 19 K with quantum numbers n=3; l=0 is/are:
1. 2
2. 1
3. 4
4. 3