Answer:
The answer is "17200 years".
Explanation:
Given:
Let the half-life of carbon-14, is beta emitter, is
Constant decay
The artifact age 

Answer:
D
Explanation:
NO and O2 are both colourless gas. and its product is brown. thus when a brown gas is produced, you can say that NO and O2 reacted to form NO2
Heat require to boil 15.6 g iron from 122 C0to 355 C0 whereas,

Where, m is mass of iron
s is specific heat of iron
d T is change in temperature in celcius

If
1 cal = 4.2 J
Then,

Thus 0.389 k cal of enrgy is required by a 15.6 g Fe to reach to 355 C^0