<u>Answer:</u> The tree was burned 16846.4 years ago to make the ancient charcoal
<u>Explanation:</u>
The equation used to calculate rate constant from given half life for first order kinetics:

where,
= half life of the reaction = 5715 years
Putting values in above equation, we get:

Rate law expression for first order kinetics is given by the equation:
![k=\frac{2.303}{t}\log\frac{[A_o]}{[A]}](https://tex.z-dn.net/?f=k%3D%5Cfrac%7B2.303%7D%7Bt%7D%5Clog%5Cfrac%7B%5BA_o%5D%7D%7B%5BA%5D%7D)
where,
k = rate constant = 
t = time taken for decay process = ? yr
= initial amount of the sample = 100 grams
[A] = amount left after decay process = 13 grams
Putting values in above equation, we get:

Hence, the tree was burned 16846.4 years ago to make the ancient charcoal
1 mole ----------- 22.4 L ( at STP )
3.5 mols --------- ?
V = 3.5 x 22.4 / 1
V = 78.4 L
hope this helps!
A COVALENT BOND, FORMS BETWEEN ELEMENTS WITH SIMILAR ELECTRONEGATIVITY AS SHARING OF ELECTRON PAIRS BETWEEN ATOMS IS EASIER AS THEY ARE IDENTICAL.
Explanation:
Bonding atoms with similar electronegativity values form covalent bonds.
A covalent bond, also called a molecular bond, is a chemical bond that involves the sharing of electron pairs between atoms.
Covalent bonds form between two nonmetal atoms with identical or relatively close electronegativity values
Electronegativity is a measure of the tendency of an atom to attract a bonding pair of electrons, also it is the strength an atom has to attract a bonding pair of electrons to itself.
Pure covalent bonds result when two atoms of the same electronegativity bond. This occurs only when two atoms of the same element bond with each other.
Answer:
400 meters every 20 seconds
Explanation:
We are given the chemical reaction and the amount of reactant used for the process. We use these data together to obtain what is asked. We do as as follows:
0.882 mol H2O2 ( 1 mol O2 / 2 mol H2O2 ) = 0.441 mol O2 produced
Hope this answers the question.