<h3><u>Answer;</u></h3>
= 11,460 years
<h3><u>Explanation;</u></h3>
- <em><u>The half life of Carbon-14 is 5,730 years
. Half life is the time taken by a radioactive material to decay by half of its original mass. Therefore, it would take a time of 5730 years for a sample of 100 g of carbon-14 to decay to 50 grams</u></em>
<em>The initial amount of carbon-14 in this case was 1 whole; thus; </em>
<em>1 → 1/2 →1/4</em>
<em>To contain 1/4 of the value, 2 half-lives have passed.
</em>
<em>But, 1 half life = 5,730 years</em>
<em>Therefore; The artifact is is therefore: 2 x 5,730
</em>
<em> = 11,460 years </em>
Answer:
Rb: [Kr] 5s
Step-by-step explanation:
Rb is element 37, the first element in Period 5.
It has one valence electron, so its valence electron configuration is 5s.
The noble gas configuration uses the symbol of the previous noble gas as a shortcut for the electron configurations of the inner electrons.
The preceding noble gas is Kr, so the electron configuration is Rb: [Kr] 5s.
Answer:
5.7 moles of O2
Explanation:
We'll begin by writing the balanced decomposition equation for the reaction. This is illustrated below:
2KClO3 —> 2KCl + 3O2
From the balanced equation above,
2 moles of KClO3 decomposed to produce 3 moles of O2.
Next, we shall determine the number of mole of O2 produced by the reaction of 3.8 moles of KClO3.
Since 100% yield of O2 is obtained, it means that both the actual yield and theoretical yield of O2 are the same. Thus, we can obtain the number of mole of O2 produced as follow:
From the balanced equation above,
2 moles of KClO3 decomposed to produce 3 moles of O2.
Therefore, 3.8 moles of KClO3 will decompose to produce = (3.8 × 3)/2 = 5.7 moles of O2.
Thus, 5.7 moles of O2 were obtained from the reaction.
Answer:
c) non polar Covalent
Explanation:
this is a molecule formed by atoms of the same element . they both have similar electronegativities and thus cancel out . This makes it a perfect Covalent molecule . The fact that it's a symmetrical molecule makes it non polar. a symmetrical molecule is a molecule formed by the overlap of orbitals of two atoms of the same element ( that is to say , there's no dipole )
