Answer:
Scientists were unsure about the last common ancestor between apes and humans because fossils are so scarce, researchers do not know what the last common ancestors of living apes and humans looked like or where they originated.
Explanation:
Gold is found in pure state in nature but not the iron because gold is un-reactive metal, so it does not react with other element in normal condition but iron is reactive metal so it reacts with atmospheric oxygen in presence of moist (water) to form oxide.
Explanation:
I hope it'll help you.
Answer:
Potassium
1s2 2s2 2p6 3s2 3p6 4s1
Explanation:
The atom having only one electron its outermost shell must belong to an element in group one of the periodic table.
Having noted that, we proceed to find out what element in group one that has the atom just described in the question.
That atom must belong to an element in the fourth period. The only group 1 element in the fourth period is potassium.
The electron configuration of potassium is;
1s2 2s2 2p6 3s2 3p6 4s1
The volume of SO2 produced at 325k is calculated as below
calculate the moles of SO2 produced which is calculated as follows
write the reacting equation
K2SO3 +2 HCl = 2KCl +H2O+ SO2
find the moles of HCl used
=mass/molar mass = 15g/ 36.5 g/mol =0.411 moles
by use of mole ratio between HCl to SO2 which is 2:1 the moles of SO2 is therefore = 0.411 /2 =0.206 moles of SO2
use the idea gas equation to calculate the volume SO2
that is V=nRT/P
where n=0.206 moles
R(gas constant) = 0.082 L.atm/ mol.k
T=325 K
P=1.35 atm
V=(0.206 moles x 0.082 L.atm/mol.k x325 k)/1.35 atm = 4.07 L of SO2
Answer:
The answer to your question is 24.325
Explanation:
Data
Magnesium-24 Abundance = 78.70%
Magnesium-25 Abundance = 10.13%
Magnesium-26 Abundance = 11.17%
Process
1.- Convert the abundance to decimals
Magnesium-24 Abundance = 78.70/100 = 0.787
Magnesium-25 Abundance = 10.13/100 = 0.1013
Magnesium-26 Abundance = 11.17/100 = 0.1117
2.- Write an equation
Average atomic mass = (Atomic mass-1 x Abundance 1) + (Atomic mass 2 x
Abundance-2) + (Atomic mass 3 x Abundance 3)
3.- Substitution
Average atomic mass = (24 x 0.787) + (25 x 0.1013) + (26 x 0.1117)
4.- Simplification
Average atomic mass = 18.888 + 2.533 + 2.904
5.- Result
Average atomic mass = 24.325
