Answer:
He will use a radioactive element with a long half life of greater than 1 billion years
Explanation:
Rocks are an aggregation of solid mass which is usually rich in minerals. The age of rocks is established using radiometric dating method.
According to Oxford Dictionary, radiometric dating is "a method of dating geological specimens by determining the relative proportions of particular radioactive isotopes present in a sample."
The age of rocks can only be ascertained using isotopes that have very long half lives because many of these rocks are very old (aged billions of years) hence their age can only be determined using elements that has a half life greater than 1 billion years.
Answer:
Coal gas is a flammable gaseous fuel made from coal and supplied to the user via a piped distribution system.It is produced when coal is heated strongly in the absence of air. ... Facilities where the gas was produced were often known as a manufactured gas plant (MGP) or a gasworks.
Coal tar is a thick dark liquid which is a by-product of the production of coke and coal gas from coal. It has both medical and industrial uses. Medicinally it is a topical medication applied to skin to treat psoriasis and seborrheic dermatitis (dandruff). It may be used in combination with ultraviolet light therapy.
: a bituminous coal suitable for making into coke.
Human evolution known to be a process in which species adapt to certain conditions of life, and in the battle of life and death, they are forced to become stronger in order to survive in this world. Diseases have always been present during the evolution, acting themselves as a natural selectors - the weaker organisms get sick and die. Not just humans, but all species have to establish a great protecting mechanism in order to survive. That is how our bodies are built, to be able to withstand and survive in the conditions we live in, and that is why our immune system has to be taken care of.
Answer:
B cells develop into plasma cells that make antibodies to fight infection.
