The element having atomic number 19, is:
1. an inert gas
2. a metal with oxidation number +1
3. a non-metal with oxidation number -3
4. a metal with oxidation number -3
Which of the following has the least density?
1. Na
2. Li
3. Mg
4. K
The order of basic character of given oxides is:
1. Na2O > MgO > Al2O3 > CuO
2. MgO > Al2O3 > CuO > Na2O
3. Al2O3 > MgO > CuO > Na2O
4. CuO > Na2O > MgO > Al2O3
An element R forms the highest oxide R2O5. R belongs to:
1. 13th group
2. 15th group
3. 16 th group
4. 2nd group
Transition elements exhibit variable oxidation states because they release electrons from the following orbits:
1. ns and np orbits
2. (n-1)d and ns orbits
3. (n-1)d orbits
4. ns orbits
The outer electronic configuration of Gd (Atomic no. 64) is:
1. 4f3 5d56d2
2. 4f8 5d106d2
3. 4f4 5d46d2
4. 4f7 5d16s2
Which of the following transition metal ions has the lowest density?
1. Copper
2. Nickel
3. Scandium
4. Zinc
Which one is a metalloid?
1. Tin
2. Germanium
3. Sulphur
4. Carbon
Elements with an electronic configuration 1s2 2s22p6 3s23p63d10 4s24p64d10 5s25p3 belong to the group :
1. | 3rd | 2. | 15th |
3. | 17th | 4. | 2nd |
General electronic configuration of the transition elements is given by:
1. ns2nd1-10
2. ns2np6nd1-10
3. (n-1)d1-10np6
4. (n-1)d1-10ns1-2