Type the correct answer in the box. express your answer to three significant figures.

the half-life of carbon-14 is 5,730 years. dating organic material by looking for c-14 can’t be accurately done after 50,000 years.

suppose a fossilized tree branch originally contained 4.30 grams of c-14. how much c-14 would be left after 50,000 years?

use the formula n = n0 .

a tree branch that originally had 4.3 grams of carbon-14 will have
grams after 50,000 years.

A tree branch that originally had 4.3 grams of carbon-14 will have  9.4586 x 10⁻³ grams after 50,000 years.

Explanation:

The integral rate law of a first order reaction:

kt = ln ([A₀]/[A]),

where, k is the rate constant of the reaction,

t is the time of the reaction (t = 50,000 years),

[A₀] is the initial concentration of carbon-14 ([A₀] = 4.30 g).

[A] is the remaining concentration of carbon-14.

k = ln 2/(t1/2) = 0.693 / (5,730 years) = 1.21 x 10⁻⁴ years⁻¹.

∵ kt = ln ([A₀]/[A]).

(1.21 x 10⁻⁴ years⁻¹)(50,000 years) = ln ((4.30 g)/[A]).

6.047 = ln ((4.30 g)/[A]).

Taking the exponential of both sides:

422.893 = ((4.30 g)/[A])

∴ [A] = (4.30 g)/(422.893) = 9.4586 x 10⁻³ g.

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.