Answer:
We have 1.361 moles in the sample
Explanation:
Mass of iron = 76.02g
Molar mass of iron = 55.845 g/ mole ( This we can find in the periodic table, and menas that 1 mole of iron has a mass of 55.845 g).
To calculate the number of moles we will use following formula:
moles (n) = mass / molar mass
moles iron = 76.02g / 55.845 g/ mole
moles iron = 1.36127 moles
To use the correct number of significant digits we use the following rule for multiplication and division :
⇒ the number with the least number of significant figures decides the number of significant digits.
⇒76.02 has 4 digits ( 2 after the comma) and 55.845 has 5 digits (3 after the comma).
⇒ this means 1.361 moles
We have 1.361 moles in the sample
Answer:
-a nonmetal is a substance that lacks the characteristics of a metal.
-Seventeen elements are generally classified as nonmetals: most are gases (hydrogen, helium, nitrogen, oxygen, fluorine, neon, chlorine, argon, krypton, xenon and radon); one is a liquid (bromine); and a few are solids (carbon, phosphorus, sulfur, selenium, and iodine).
I believe it is D as you are hearing the copper tube
If two protons are added to carbon, the chemical identity changes to oxygen, which is two spaces over horizontally on the periodic table. The number of protons is what we call the atomic number (Z), and this is what defines the identity of an element. Since we also added two neutrons, this is simply oxygen, or oxygen-16, the most abundant isotope of oxygen.
The percentage by mass of oxygen in the compound
find the total mass=( 1.900+ 0250 +0.850) = 3
the percentage mass mass of oxgyen/total mass x100
that is (0.850/3) x100=28.33%
