It is so because warm air is lighter than cold air. Cold air means the molecules are not moving as much, so they will feel like sticking together and will not jump around as molecules in warm air will(higher temp. means higher KE). Think of a solid, colder solids are much heavier than warmer ones(think of ice-starts melting).
Answer:
period 3 and group 3
Explanation:
I'm saying group 3 because that is how I learnt it at school, but if you count it then it's in group 13.
Answer: molecular formula = C12H16O8
Explanation:
NB Mm CO2= 44g/mol
Mm H2O= 18g/mol
Moles of CO2 = 36.86/44=0.84mol
0.84mole of CO2 has 0.84 mol of C
Moles of H2O = 10.06/18= 0.56mol
1mol of H20 contains 1mol of O and 2 mol H,
Hence there are 0.56mol O and (0.56×2)mol H
Hence the compound contains
C= 0.84 mol H= 1.12mol O=0.56mol
Divide through by smallest number
C= 0.83/0.56= 1.5mol
H= 1.12/0.55= 2mol
O= 0.56/0.56= 1mol
Multiply all by 2 to have whole number of moles = 3:4:2
Hence empirical formula= C3H4O2
(C3H4O2)n = 288.38
[(12×3) + 4+(16×2)]n= 288.38
72n=288.38
n= 4
:. Molecular formula=(C3H4O2)4= C12H16O8
Answer:
C. chromium is a metal that is less reactive than sodium.
Explanation:
Hello.
Given the options:
A. chromium is a nonmetal and therefore a good conductor of heat and electricity
.
B. chromium is a metal that is more reactive than potassium
.
C. chromium is a metal that is less reactive than sodium
.
D. chromium is a noble gas that is not reactive.
In this case, since chromium is in period 4 group VIB we infer it is a transition metal which slightly reacts with acids and poorly reacts with oxygen and other oxidizing substances. Thus, in comparison with both sodium and potassium which are highly reactive even with water as they get on fire, we can say that it is less reactive than both potassium and sodium, therefore, answer is: C. chromium is a metal that is less reactive than sodium.
Best regards.
