Answer: 2948
Explanation:
Half life is the amount of time taken by a radioactive material to decay to half of its original value.
Expression for rate law for first order kinetics is given by:
where,
k = rate constant = 
t = age of sample = ?
a = let initial amount of the reactant = 100
a - x = amount left after decay process = 
Thus the fossil is 2948 years old.
What's the problem ? Hardness is not the definition of a metal.
You need to expand your thinking. EVERY element is solid, liquid, and gas, over different ranges of temperature ... including all of the metals. There are only TWO elements that are liquid AT ROOM TEMPERATURE, and mercury is one of them. But on a mild day at the south pole, mercury is solid too.
Answer:
2.8 g/mL is the density of the mineral.
Explanation:
The mass, 
Volume of the object = Volume of water level rose - Initial volume of water = 30.5 mL - 20.3 mL = 10.2 mL
The expression for the calculation of density is shown below as:-
<u>2.8 g/mL is the density of the mineral.</u>
I believe the correct answer from the choices listed above is the third option. The <span>oxidation number of Nitrogen in HNO2 would be +3. It is calculated as follows:
1 + x + (-2)(2) = 0
x = +3
Hope this answers the question. Have a nice day.</span>
