All four answers are right 100%.
Answer:
% Mass of sand = 35.95%
% Mass of KBr = 64.05%
Explanation:
From the question given, we obtained the following:
Mass of mixture( KBr + sand) = 10g
Mass of sand = 3.595g
Mass of KBr = 10 — 3.595 = 6.405g
% Mass of sand = ( Mass of sand / mass of mixture) x 100
% Mass of sand = (3.595 / 10) x100
% Mass of sand = 35.95%
We can obtain the percentage of KBr by subtracting the percentage of sand from 100. This is illustrated below:
% Mass of KBr = 100 — 35.95
% Mass of KBr = 64.05%
Low melting points and boiling points. ...Low enthalpies of fusion and vaporization These properties are usually one or two orders of magnitude smaller than they are for ionic compounds.Soft or brittle solid forms. ...Poor electrical and thermal conductivity.
The exothermic process is a process or reaction that involves a release of energy from the system to its surroundings in various forms usually through heat, light, electricity or sound. In the four given choices, when melting a copper, you try to immerse the metal in heaping coals of fire. The metal will absorb the thermal energy coming from the coal, thus, once you retrieve the metal back, light will be emitted from it as well as heat.
Therefore, the answer is B. MELTING OF COPPER