In, 1937 Lawrence, in operating his cyclotron, bombarded a molybdenum-96 foil with deuterium ions (2h), producing for the first time an element not found in nature. He was initially unaware that the radioactivity produced by the "bombarded foil" was not from molybdenum but from a new, artificial element. It was his cooperation with Italian-American physicist <span>Emilio Segrè </span>that allowed the new element to be discovered. The answer is Technetium: Tc
Answer:
The atomic mass of the boron atom would be <em>10.135</em>
Explanation:
This is generally known as relative atomic mass.
Relative atomic mass or atomic weight is a physical quantity defined as the ratio of the average mass of atoms of a chemical element in a given sample to the atomic mass of 1/12 of the mass of a carbon-12 atom. Since both quantities in the ratio are masses, the resulting value is dimensionless; hence the value is said to be relative and does not have a unit.
<em>Note that the relative atomic mass of atoms is not always a whole number because of it being isotopic in nature.</em>
- <em>Divide each abundance by 100 then multiply by atomic mass</em>
- <em>Do that for each isotope, then add the two result. Thus</em>
Relative atomic mass of Boron = (18.5/100 x 11) + (81/100 x 10)
= 2.035 + 8.1
= 10.135
Percent yield is 23.11 % when 162.8 g of CO2 are formed from the reaction of excess amount of C8H18 and with 218.0 grams of O2.
Explanation:
Balanced equation for the chemical reaction:
2C8H18 + 25O2 → 16CO2 + 18H2O
data given:
CO2 formed (actual yield) = 162.8 grams
mass of oxygen = 218 grams
16 moles of CO2 formed when 5 moles of oxygen reacted
3.6 moles of CO2 formed when 6.8 moles of oxygen reacted.
In the reaction 16 moles of CO2 will have 44.01 x 16
theoretical yield of CO2 = 704.16 grams
percent yield = 
x100
putting the values in the above equation
percent yield = 
x 100
= 0.23 x 100
= 23.11 %
Percent yield is 23.11 %.
Answer:
Water, air, and food.
Explanation:
All living things need air water and food to live.
