A wooden artifact from a Chinese temple has a 14C activity of 42.8 counts per minute as compared with an activity of 58.2 counts per minute for a standard of zero age. Part A From the half-life for 14C decay, 5715 yr, determine the age of the artifact.

Answer : The age of the artifact is,

Explanation :

Half-life = 5715 years

First we have to calculate the rate constant, we use the formula :

Now we have to calculate the time taken to decay.

Expression for rate law for first order kinetics is given by:

where,

k = rate constant

t = time taken by sample = ?

a = initial activity of the reactant  = 58.2 counts per minute

a - x = activity left after decay process  = 42.8 counts per minute

Now put all the given values in above equation, we get

Therefore, the age of the artifact is,

alkaline metals are lithium, sodium, rubidium, potassium, cesium and francium.

alkali metals have electronegativity from 0.7 to 1, lowest in periodic table of elements, which means that alkali metals (i group in periodic table) has positive oxidation number in compounds.

electronegativity is a chemical property that describes the tendency of an atom to attract a shared pair of electrons towards itself.

alkaline metals (far left in main group) have lowest ionizations energy and easy remove valence electrons,

for example, potassium is the alkali metal and has a single valence electron in the outer electron shell.

electron configuration of potassium is: ₁₉k 1s²2s²2p⁶3s²3p⁶4s¹.

they can not exist alone in nature, because they are very reactive.

the answer is:  

line graphs show patterns in data with variables that change over time; whereas, circle graphs show data as parts out of a whole (such as out of 100%).