I believe the answer is B!
Answer : The time passed in years is 
Explanation :
Half-life of carbon-14 = 5730 years
First we have to calculate the rate constant, we use the formula :
Now we have to calculate the time passed.
Expression for rate law for first order kinetics is given by:
where,
k = rate constant = 
t = time passed by the sample = ?
a = initial amount of the reactant disintegrate = 15.3
a - x = amount left after decay process = 14.8
Now put all the given values in above equation, we get
Therefore, the time passed in years is
Answer:
Explanation:
1) Find number of each of the type of atom that is present in the compound, using the chemical formula .
2) Then multiply number of atoms of each element that is present in the compound with the atomic weight of each of the element
3) Add everything together and add the units (grams/mole ) after the number
Let finds that of water
Chemical formula of water is (H20 )
hydogens atoms= 2
oxygen atom= 1
Atomic weight for Hydrogen= 1
Atomic weight for Oxygen= 16
Total number of atoms of Hydrogen from the formula (H2O)= 2
Total number of atoms of Oxygen from the formula (H2O)= 1
the molar mass=
Hydrogen: ( 2 x 1)= 2
Oxygen: ( 1 x 16)= 16
Add together= (16+2)
= 18
Then add the unit, we have(18 g/mol.)
Electrons are electrochemically negatively charged particles that move random around the nucleus. They have a relatively small mass compared to Protons and Neutrons. They are found in electron clouds that surround the nucleus and their movement and properties provide for the bonding characteristics of each atom.
