Answer:
3,4
Explanation:
Hydrogen has no other electron hence there is no screening of the valence electron by inner electrons. It is the lightest known element with a relative molecular mass of 2. Screening effect refers to the fact that inner or core electrons prevent the outermost electron from feeling the attractive force of the nucleus.
Answer:
seven electrons
Explanation:
Chlorine is present in group seventeen of periodic table. It is halogen element. All halogens have seven electrons in outer most valance shell.
The require only one electron to gain the stable electronic configuration or to complete the octet.
Electronic configuration of chlorine:
Cl₁₇ = 1s² 2s² 2p⁶ 3s² 3p⁵
Abbreviated electronic configuration:
Cl₁₇ = [Ne] 3s² 3p⁵
Properties of chlorine:
1. it is greenish-yellow irritating gas.
2. its melting point is 172.2 K
3. its boiling point is 238.6 K
4. it is disinfectant and can kill the bacteria.
5. it is also used in manufacturing of paper, paints and textile industries.
Answer:
true
Explanation:
one reason is because plants need sunlight and water because it is their source of food
Answer:
Explanation:
The actual boiling point is probably between 34C and 40C.
