Advertisements
Advertisements
Question
Name the following:
An element having valency 'zero'
Advertisements
Solution 1
Helium
Solution 2
Element He, Ne, Ar i.e. Noble gases have ‘zero’ valency.
RELATED QUESTIONS
Five atoms are labelled from A to E.
| Atoms | Mass No. | Atomic No. |
| A | 40 | 20 |
| B | 19 | 9 |
| C | 7 | 3 |
| D | 16 | 8 |
| E | 14 | 7 |
(a) Which one of these atoms:
(i) contains 7 protons,
(ii) has an electronic configuration 2, 7?
(b) Write down the formula of the compound formed between C and D.
(c) predict which are: (i) metals, (ii) non-metals?
Give electron dot diagram of the following:
nitrogen
State differences between the properties of ionic compounds and covalent compounds.
How are X-rays produced?
Identify the following reaction as either oxidation or reduction:
O + 2e- → O2-
In the formation of magnesium chloride (by direct combination between magnesium and chlorine), name the substance that is oxidized and the substance that is reduced.
How do atoms attain Noble gas electronic configuration?
Draw the electron distribution diagram for the formation of Carbon di oxide (CO2 ) molecule.
Match the following:
| 1. | Monoatomic gaseous atom | a. | Electrovalent bond |
| 2. | Octet rule | b. | Benzene |
| 3. | Ionic bond | c. | Water |
| 4. | Non-polar solvent | d. | Electronic theory of valence |
| 5. | Polar solvent | e. | Noble gases |
Choose the odd one out and write the reason:
