Chemistry
Which of these statements gives the correct picture regarding halogens and alkali metals with respect to an increase in the atomic number ?
- Reactivity decreases in alkali metals but increases in halogens.
- Reactivity increases in both.
- Reactivity decreases in both.
- Reactivity increases in alkali metals but decreases in halogens.
Answer
Reactivity increases in alkali metals but decreases in halogens.
Reason — Atomic number increases while going down the group in alkali metals and halogens. The tendency of losing electrons increases down the group. Reactivity of metals depends on tendency to lose electrons, thus reactivity of alkali metals increases while going down the group. Reactivity of non-metals depends on tendency to gain electrons, thus reactivity of halogens decreases while going down the group.
Related Questions
In the periodic table while going down in the halogen group :
- reactivity will increase
- electronegativity will increase
- ionic radius will increase
- ionisation potential will increase
Electron affinity is the :
- Power of an atom to attract an electron to itself.
- Energy released when an electron is added to an isolated atom in the gaseous state.
- Energy absorbed when an electron is added to an isolated atom in the gaseous state.
- Energy required to remove an electron from an isolated gaseous atom.
The correct order of increasing ionisation energy of Be, Mg, Ca, Sr is :
- Be, Mg, Ca, Sr
- Ca, Mg, Be, Sr
- Sr, Ca, Mg, Be
- Mg, Ca, Sr, Be
An element 13X combines with 17Y to form a compound. which of the following is true ?
P → X is a metal, Y is a metal.
Q → X is a metal, Y is a non-metal.
R → X losses electron(s), y gains electron(s).- Only P
- Only Q
- Both P and Q
- Both Q and R