i think helium hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh
Answer:
The answer to your question is below
Explanation:
1.-
a) Look for the mass number of Gold in the periodic table
Mass number = 197 g
Use proportions to answer this question
197 g of gold ------------- 6.023 x 10 ²³ atoms
4.64 g of gold ---------- x
x = (4.64 x 6.023 x 10²³) / 197
x = 1.42 x 10²² atoms
2.- mass of 4.12 x 10²⁴ molecules of glucose
Molecular mass = (6 x 12) + (12 X 1) + (6 x 16)
= 72 + 12 + 96
= 180 g
180 g of glucose ------------------- 6.023 x 10 ²³ molecules
x ------------------- 4.12 x 10 ²⁴ molecules
x = (4.12 x 10²⁴ x 180) / 6.023 x 10²³
x = 1231.3 g of glucose
The number of years that must be invested at a rate of 7 % to earn$ 303.52 in interest is
8 years
<em><u>calculation</u></em>
- <em><u> </u></em><em>by use of the formula A = P (1+ rt) </em>
- <em> where : A is the final amount = 542 + 303.52 =$ 845.52</em>
<em> P is the principal money to be invested = $ 542</em>
<em> r= rate= 7/100=0.07</em>
<em> t= time required</em>
<em>=$ 845.52=$ 542( 1+ 0.07 t)</em>
- <em>open the bracket</em>
- <em>= $845.53= $542 + $37.94 t</em>
- <em>like terms together</em>
=$ 845.53 -$542 = $37.94 t
=$303.52 =$37.94 t
- divide both side by $37.94
= $303.52/ $ 37.94 = $37.94t/$37.94
t= 8 years
