Advertisements
Advertisements
Question
Write scientific reason.
Generally the ionic compounds have high melting points.
Solution
- Ionic compounds are composed of cations and anions.
- These ions are held together by strong electrostatic forces of attraction.
- Considerable amount of energy is required to break these strong forces of attraction.
Hence, the melting points of ionic compounds are high.
RELATED QUESTIONS
Mark ‘T’ if the statement is true and ‘F’ if it is false.
Copper displaces zinc from zinc sulphate solution. ( )
What happens when Dilute sulphuric acid is poured on a copper plate?
Write word equations of the reactions involved.
State one use of Mercury.
Name one ore of manganese. Which compound of manganese is present in this ore? Also write its chemical formula.
Mention two uses of the following metals and non-metals
Aluminium
Mention two uses of the following metals and non-metals
Oxygen
A metal with melting point less than 50°C is
State two important uses of following metal
Uses of copper
State two important uses of following metal
Uses of aluminium
Why is hydrogen placed with alkali metals?
Write name.
Alloy of sodium with mercury.
When a copper coin is dipped in silver nitrate solution, a glitter appears on the coin after some time. Why does this happen? Write the chemical equation.
What is it made from? Why?
A pair of tongs.
With reference to the following metals state their use in daily life metal:
iron
Name the following:
The most reactive halogen.
Compare the properties of metals and nonmetals. Give three examples for each.
Higher Order Thinking Skills.
Aakash noticed that the metal latch on gate was difficult to open during hot sunny days. However, it was not difficult to open the same latch at night. Aakash observed that the latch and the gate are exposed to the sun during day time.
- Formulate a hypothesis based on the information provided.
- Briefly state how you would test the hypothesis.
______ is the first scientist who used the term element.
Match the following
| i. | Softest metal | a. | Copper |
| ii. | Hardest metal | b. | Sodium |
| iii. | Hardest non–metal | c. | Osmium |
| iv. | Ductility | d. | Diamond |
Match the following
| i. | Silica | a. | Caustic potash |
| ii. | Potassium hydroxide | b. | Sand |
| iii. | Sodium hydroxide | c. | Calamine |
| iv. | Zinc carbonate | d. | Caustic soda |
