Question

please answer this all questions​

Answer 1

Answer:

4.Exothermic reactions are reactions or processes that release energy, usually in the form of heat or light.

3.Thermal decomposition reaction.

Electrolytic decomposition reaction.

Photo decomposition reaction.

5.(a)Mg (b)ca (d)Na

Answer 2

Answer:

Q3ans: Three types of decomposition reactions are:

(1) Thermal decomposition reaction.

ex: CaCO3 (s) + heat - CaO (s) + CO2 (g).

(2) Electrolytic decomposition reaction.

ex: 2H2O - 2Na +cl2.

(3) photo decomposition reaction.

Q4ans: Reaction which is accompanied by rise in temperature, in which heat is evolved .

for ex: when water is added to quick time (CaO) , taken in a beaker slaked lime (Ca(OH2) is formed , and beaker is found to be quite hot.

Q5ans:(a) Mg, (b) Ca, (c) Fe, (d) Na.

Q7ans: To prevent corrosion:

(a) use non corrosive metals, such as stainless steel or aluminum.

(b) make sure that the metal surface stays clean and dry.

(c) use drying agents.

(d) use a coating or barriers product such grease , oil ,paint or carbon fiber coating .

(e) lay a layer of backfill, for example limestone, with underground piping.

Q8ans: The ability to do work is called energy.

SI unit of energy is Joule.

Q9ans: electric current is the rate of flow of electric charge, no current can flow if the circuit is broken . for example, when a switch is open, an electric current flows when electrons move through a conductor , such as a metal wire . Metals are good conductor of electricity.

Q10ans: SI unit of charge is coulomb .It is represents by C.