Answer:
Some metals can be extracted from compounds by heating with carbon atom because they are less reactive than carbon and some metals cannot be extracted because they are more reactive than carbon atom.
Explanation: If the metal is less reactive than carbon atom so the carbon atoms make bond with oxide or other atom present with metal and the metal is free from that oxide or that element. But if the reactivity of metal is higher than carbon is unable to remove the oxide or element.
It should be option (A) because conduction is the transfer of heat energy from one place to another by vibrations/motion of the molecules. I hoped I helped.
Answer:C
Explanation:
A process is called spontaneous if the process takes place on its own without the intervention of external factors.
The spontaneous processes are generally quick with observable rates of reaction.But processes can be spontaneous even with negligible rates of reaction.
Spontaneity of reactions depend on temperature.
This is because spontaneity is measured by gibbs energy or enthalpy.
Both of these measures are dependent on temperature.
So,temperature affects spontaneity.
The strength of an Arrhenius base determines percentage of ionization of base and the number of OH⁻ ions formed.
Strong base completely ionize in water and gives a lot of hydroxide ions (OH⁻), for example sodium
hydroxide: NaOH(aq) → Na⁺(aq)
+ OH⁻(aq).
Weak base partially ionize in water and gives a few hydroxide ions (OH⁻), for example ammonia: NH₃ + H₂O(l) ⇄ NH₄⁺(aq) + OH⁻(aq).
<u>Answer:</u> The mass of phosphorus that is present for given amount of calcium is 28.53 g.
<u>Explanation:</u>
We are given:
Mass of calcium = 50 grams
The chemical formula of calcium phosphate is 
Molar mass of calcium = 40 g/mol
Molar mass of phosphorus = 31 g/mol
In 1 mole of calcium phosphate, 120 grams of calcium is combining with 62 grams of phosphorus.
So, 50 grams of calcium will combine with = 
of phosphorus.
Hence, the mass of phosphorus that is present for given amount of calcium is 28.53 g.
