All categories

3 years ago

Which group of elements are the most important for living organisms?\

2 answers:

6 0

B- Carbon nitrogen and oxygen. All organisms are made up of carbon, oxygen is essential to breath, and nitrogen makes up most of earth's atmosphere.

Serhud [2]3 years ago

4 0

The answer is b carbon nitrogen and oxygen

You might be interested in

Which gas has. an atomic mass of 15.999

sveticcg [70]

Answer: Oxygen (O)

Explanation:

8 0

3 years ago

Read 2 more answers

. Monthly measurements of atmospheric CO2 concentration at Mauna Loa began in March 1958. The average CO2 concentration for that

Harrizon [31]

Answer:

$Increase=98.8ppm$

$Average\ increase/year=1.594\frac{ppm}{year}$

Explanation:

Hello,

In this case, since the nowadays concentration of CO2 is 414.51 ppm and the concentration in 1958 was 315.71 ppm, the total increase is computed via the difference between them:

$Increase=414.51ppm-315.71ppm\\\\Increase=98.8ppm$

Moreover, the average increase per year is computed considering that from 1958 to 2020, 62 years have passed, therefore, such average is:

$Average\ increase/year=\frac{98.8ppm}{62 years} \\\\Average\ increase/year=1.594\frac{ppm}{year}$

Regards.

4 0

3 years ago

Select the name of the element with a condensed ground-state electron configuration of [kr] 5s14d7.

Vilka [71]

elements have equal number of protons and neutrons

the condensed format is when the closest noble gas with the closest electron configuration is given, this closest noble gas atomic number should be lesser than the atoms atomic number

atomic number of Kr is 36

1 electron in 5s subshell and 7 electrons in 4d subshell.

there's a total of 36 + 1 + 7 = 44 electrons

atomic number of the atom is 44

element with atomic number 44 is Ruthenium - Ru

answer is Ru

7 0

3 years ago

Read 2 more answers

When did the level of oxygen in Earth's atmosphere become high enough to sustain aerobic respiration? When did the level of oxyg

Alexeev081 [22]

Answer:

2.4 billion years ago

Explanation:

The formation of the tertiary atmosphere, with the re-arrangements of the plates, took that influenced the long term evolution of the planet that transferred the carbon dioxide to the large continental stores and the surplus oxygen came into formation about 2.4 billion years ago during the massive oxygenation event that leads to the appearance at the end of the banded iron formations.

The process of photosynthesis also added and reduced the material that reduces the oxidation of the atmosphere and kept ion place till 15% of the Precambrian period had ended.

7 0

3 years ago

Atoms from different substances can never combine with atoms from other substances. Disagree or agree reason why ?

uysha [10]

Disagree, because they can come together to form a compound element. Hope it helped!

5 0

4 years ago