I took the test I think the guy above is correct I’m not to sure good luck thanks
Answer : The correct option is, (a) Synthesis
Explanation :
Synthesis reaction : A chemical reaction where multiple substances or reactants combine to form a single product.
It is represented as,

Combustion reaction : A chemical reaction in which a hydrocarbon react with the oxygen to give product as carbon dioxide and water.
It is represented as,

Single replacement reaction : A chemical reaction in which the more reactive element replace the less reactive element.
It is represented as,

In this reaction, A is more reactive element and B is less reactive element.
Double replacement reaction : It is a type of chemical reaction where a positive cation and a negative anion of two reactants exchange places to form two new products.
It is represented as,

(X and A are the cations, Y and B are the anions)
The given reaction is, 
In this reaction, calcium combine with the chloride to form calcium chloride as a product.
Hence, the given type of reaction is a synthesis reaction.
Answer:
The correct option is;
(b) 0.8 Tm
Explanation:
Sintering is a form of heat treatment given to introduce a material in powdery form in order to introduce the properties of integrity and strength
by the application of heat to the powder at a temperature below its melting point.
With regards to imparting favorable metal properties in the metal to undergo sintering such as ductility, toughness, porosity, hardness, strength it is required to select a sintering temperature higher than 0.6 - 0.8 Tm.
A hydrate is a substance that contains water or its constituent elements. When this substance is heated, water is evaporated leaving an unhydrate. From this sample, the amount of water present would be equal to 2.73 g. Hope this answers the question. Have a nice day.
In chemical changes molecules in the reactants interact to form new substances, which mean means are broken up to form new bonds. No atoms are created or destroyed while undergoing the chemical change. In a physical change more like a state of change meaning shape, size or anything that effects how the object looked before then no new substances are formed.