Answer:
the number of molecules in 7g nitrogen
Ans) 7 gram of Nitrogen contains 1.5×10^23 molecules =1.5e+23
Answer:
its a trick yo have to add it all
Explanation:
Radioactive elements obey 1st order kinetics,
For 1st order reaction, relation between rate constant (k) and half life [t(1/2)] is,
k =

Also, for 1st order reaction, we have
t =
Given that: <span>the bones from a mastodon had lost 78.5% of their C14,
</span>∴ initial conc. of C14 = 100%, conc. of C14 left after time 't' = 21.5%
∴t =

= 1.2758 X 10^4 hours
Answer:
Atomic Number: 35
Number of Neutrons: 2
Explanation:
The number of protons and electrons are the same, so given that this element has 35 electrons, it also has 35 protons.
Atomic number is the number of protons, so it is 35.
Mass number is the number of protons + neutrons, so take the mass number of 37 and subtract the 35 protons to get 2 neutrons.