Answer:
B
Explanation:
Isotopy is a phenomenon in which there exists two or more kind of atoms of the same element. These atoms have the same number of protons but different mass numbers. That is, they have the same atomic number but differ only by the number of neutrons in the nucleus of the atom. Now, let us apply this information to the options individually:
A. Is wrong, they are not the same element
B. Is correct. they both belong to the same element hydrogen. Infact, they are named protium and deuterium respectively
C is wrong they are not same element
D is wrong They are not elements at all
E. Is wrong, one is an element, the other is a molecule
Answer:
Molecular formula = C20H30
Explanation:
NB 440mg = 0.44g, 135mg= 0.135g
From the question, moles of CO2= 0.44/44= 0.01mol
Since 1 mol of CO2 contains 1mol of C, it implies mol of C = 0.01
Also from the question, moles of H2O = 0.135/18= 0.0075mole
Since 1 mol of H2O contains 2mol of H, it implies mol of H = 0.0075×2= 0.015 mol of H
To get the empirical formula, divide by smallest number of mole
Mol of C = 0.01/0.01=1
Mol of H = 0.015/0.01= 1.5
Multiply both by 2 to obtain a whole number
Mol of C =1×2 = 2
Mol of H= 1.5×2 = 3
Empirical formula= C2H3
[C2H3] not = 270
[ (2×12) + 3]n = 270
27n = 270
n=10
Molecular formula= [C2H3]10= C20H30
Correct answer is <span>C. They have a full shell of valence electrons. </span>
Oxidation number is defined as the total number of electrons that are gained or lost by the atom to form a chemical bond.
the oxidation number of the compound H₂S is 0.
the sum of the oxidation numbers of the individual elements should add up to the oxidation number of the compound.
(oxidation number of H x 2 H ions) + oxidation number of S = 0
since we know the oxidation number of H, lets name the oxidation number of S = x
(+1 * 2 )+ (x) = 0
2 + x = 0
x = -2
oxidation number of S is -2
Condensation occurs in a condenser