Answer:
Answer B
Explanation:
By definition mixtures are combinations of substances physically prepared and physically separated. Mixtures are classified as 'homogeneous mixtures' and 'heterogeneous mixtures'. For homogeneous mixtures all components are dissolved, with solute evenly distributed throughout the solution and assumes state of solvent. 'Heterogeneous mixtures' have inconsistent properties throughout and solute concentration is not consistent throughout the mixture.
Answer:d
Explanation:I’m not 100% sure how to explain it but I’m almost for sure it’s d.
During the day or in spring and summer, plants take up more carbon dioxide through photosynthesis than they release through respiration , and so concentrations of carbon dioxide in the air decrease. Then at night or during autumn and winter, plants reduce or even stop photosynthesising, releasing carbon dioxide back into the air. This is often called the natural carbon cycle.
Answer:
A. Modern atomic theory is, of course, a little more involved than Dalton's theory but the essence of Dalton's theory remains valid. ... Also, there are different kinds of atoms (differing by their masses) within an element that are known as "isotopes", but isotopes of an element have the same chemical properties.
B. The explanation becomes a scientific theory. In everyday language a theory means a hunch or speculation. Not so in science. In science, the word theory refers to a comprehensive explanation of an important feature of nature supported by facts gathered over time.
Answer:
1. (a) on land and offshore
2. (c) Boiling, evaporation and condensation
3.(d) Haematite and asphalt.
4. (a) octane
5.(d) petroleum gases, liquids and solids.
Explanation:
Cracking refers to the the breakdown of heavier fractions of crude oil to give the lighter fractions of crude oil having greater economic value. For instance, diesel oil may be cracked to yield gasoline which is composed of lighter hydrocarbons and has greater economic value. Cracking is of importance in the petroleum industry because it is used to produce lighter hydrocarbons from heavier ones.
Reforming is the conversion of straight chain hydrocarbons to branched chain hydrocarbons having a lesser tendency towards knocking of engines. It is very important in the petroleum industry because it leads to the production of better quality fuels with higher octane rating.
b) In Nigeria, oil producing communities are usually faced with the problem of damage to arable land due to oil exploration activities. Many oil producing communities in Nigeria are facing severe damage to the ecosystem due to oil drilling in those areas. Also, oil rich communities are at risk of crud oil spillage which contaminates water bodies and leads to loss of employment for the local people and death of aquatic animals.
