Which phrase describes the absolute age of a rock? 1does not provide an exact age 2is the number of years since it formed 3is the age compared to other rocks around it 4indicates whether it is younger or older than the rocks above it

2 is the number of years since it formed

Absolute dating can be defined as an age estimation method which gives the age of the fossil evidence on the basis of studies based upon the chronology of past geological events by examining various physical forms such as strata of sediments or rocks. The absolute dating of the earth material is a measure of how old the material is in years. This method of dating gives an accurate age of the specimen under concern. It is also called as calendar dating or chronometric dating.

On the basis of the above information, the phrase which describes the absolute age of a rock is the number of years since it formed.

step 1: nitrogen fixation- conversion of atmospheric no₂ into forms useful to plants by lightning, bacteria, and cyanobacteria.

step 2: nitrification-process of converting ammonia to nitrite or nitrate.

step 3: assimilation-plant roots absorb new form of nitrogen.

step 4: ammonification-conversion of organic nitrogen to ammonia by bacteria involved in decomposition.

step 5: denitrification-bacteria turns the decomposed matter back into n₂o, which is released into atmosphere; repeat cycle.

carbon atoms, hydrogen, oxygen, and nitrogen.