Match the year to its event in the history of environmental science

The correct answers are:

1. Paul Ehlrich argued that overpopulation was responsible for environmental problems - 1968.

Explanation: Stanford University Professor Paul R. Ehrlich and his wife, Anne Ehrlich wrote one of the best selling books - "The Population Bomb"  in 1968 and argued that overpopulation is responsible for environmental problems.

2. The first national Earth Day marked the largest demonstration in American history. - 1970

Explanation: The first national Earth Day was founded by United States Senator Gaylord Nelson on April 22, 1970.

3. President Eisenhower asked the public health service to study ways to control air pollution- 1955.

Explanation: The Air Pollution Control Act of 1955 was signed by President Dwight D. Eisenhower to study ways to control pollution.

4. The Santa Barbara oil spill led to reforms in the energy industry - 1969

Explanation: The Santa Barbara oil spill occurred in January 1969 in the Santa Barbara led to reforms in energy industry.

The following are the correct matches of the year with the events:  

1. In 1968, Paul Ehrich argued that overpopulation was responsible for environmental issues. Paul Ehrich, the Professor of the Stanford University, mentioned about the overpopulation and the environmental issues in the book the Population Bomb in 1968.  

2. In 1970, the first National Earth Day marked the largest demonstration in American history. The first National Day was founded by Gaylord Nelson, US senator, on April 22, 1970.  

3. In 1955, President Eisenhower asked the public health service to study ways to control air pollution. President Eisenhower signed the Air Pollution Control Act of 1955 in order to control air pollution.  

4. In 1969, the Santa Barbara oil spill led to the reforms in the energy industry.  

the relative atomic mass of an element is the mass of one atom of that element, relative to 1/12th of the mass of a  1212c atom. to convert to an absolute mass in kg, it is necessary to multiply by  1.661×10−271.661×10−27.

the relative atomic mass is roughly equal to the number of neutrons, plus the number of protons, in the nucleus of the atom.

for elements with more than one stable isotope (different types of nucleus with different numbers of neutrons but the same number of protons), the quoted mass is usually the average mass, weighted by the relative abundance of the different isotopes.

both male and female gametes are produced by meiosis of the germ cells. therefore, both male and female gametes are haploid. one male and one female gamete unite during the fertilization to form the diploid zygote. in seed bearing plants, pollen grain is the male gametophyte, which produces sperm cells.