Answer:
see the pic for the answer
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.
Answer:
A. During the summer, Earth's rotational axis is parallel to the Sun's rotational axis.
Explanation:
Actually, though, the Earth is tilted 23.4 degrees! (A circle is 360 degrees.) This tilt is the reason that days are longer in the summer and shorter in the winter. The hemisphere that's tilted closest to the Sun has the longest, brightest days because it gets more direct light from the Sun's rays.
Plz mark me brainliest if correct :)
Just multiply 151 x 0.0001
That will equal:
0.00151 km or if you want to round it then it would be 0.02km
Answer:

Explanation:
Hello,
In this case, we can consider that the given heat of combustion is indeed the heat of reaction since it corresponds to the combustion of propane, which is computed by using the heat formation of all the involved species as shown below:

Thus, since the heat of formation of gaseous carbon dioxide is -393.5 kJ/mol, water -241.8 kJ/mol and oxygen 0 kJ/mol, the heat of formation of propane is:

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