Answer:
Ans1) Common Shapes of Bacteria
Coccus: spherical or round
Bacillus: rod shaped
Spiral: curve, spiral, or twisted
Ans2) Bacteria are classified into five groups according to their basic shapes:
spherical (cocci),
rod (bacilli),
spiral (spirilla),
comma (vibrios) or corkscrew
(spirochaetes)
2Cu + S = Cu₂S
n(Cu)=m(Cu)/M(Cu)
n(Cu)=12.71/63.55=0.2 mol
n(S)=m(s)/M(S)
n(S)=8.000/32.01=0.25 mol
Cu:S 2:1
0.2 mol : 0.25 mol copper deficiency, sulphur in excess
theoretical mass of copper (I) sulfide
m(Cu₂S)=M(Cu₂S)n(Cu)/2
the percentage yield in the reaction is
w=m'(Cu₂S)/m(Cu₂S)=2m'(Cu₂S)/M(Cu₂S)n(Cu)
w=2*14.72/(159.16*0.2)=0.925 (92.5%)
the second one is space while the first one is shape
In order to compounds to be serparated, chemical means are needed. For example, if it you want to separate hydrogen and oxygen in the water ,an electric current should flow through it and that is a kind of chemical means(it is related to the chemical properties of the elements .)
While ,if there is a mixture ,it's components are rather separated easily in physical means. For instance, if you have a salt water, you are able to divide them by using each physical properties. Water is able to turn to a state of gas by evaporating or boiling. Using such properties, you could separate water from salt. Therefore, separating compounds and mixtures are all about the components physical or chemical properties.
So, the answer is a. I hope it will help you^^
