Answer : The final temperature of the copper is, 
Solution :
Formula used :

where,
Q = heat gained = 299 cal
m = mass of copper = 52 g
c = specific heat of copper =
= final temperature = ?
= initial temperature = 
Now put all the given values in the above formula, we get the final temperature of copper.


Therefore, the final temperature of the copper is, 
Put a thermometer in the water and wait until it boils. When it boils record the temperature and compare it to the normal water boiling point.
Answer:
D
Explanation:
Color, texture, and density are all physical properties but reactivity is a chemical property so the answer is D.
Answer:
NH2.
Explanation:
The mass of hydrogen in the sample = 1.525 - 1.333 = 0.192g.
Dividing the 2 masses by the relative atomic mass of hydrogen and nitrogen:
H: 0.192 / 1.008 = 0.1905
N: 1.333 / 14.007 = 0.09517
The ratio of N to H = 0.09517 : 0.1905
= 1 : 2.
So the empirical formula is NH2.