The answer is: D. Biological precipitation.
Biological precipitation is the deposition of minerals from solution by the agency of organisms
.
Deposition is the geological process in which sediments, soil and rocks are added to a landform or land mass.
Ocean sediments originate from numerous sources:
1) biological activity (biogenous).
2) weathering and erosion of the continents (terrigenous/lithogenous).
3) volcanic eruptions (volcanogenous).
4) chemical processes (hydrogenous).
Calcium carbonate (CaCO₃) is made of calcium, carbon and oxygen atoms.
salt and water solution is a homogeneous mixture
<u>Explanation:</u>
Homogeneous mixtures generally termed as solutions, have an identical similar occurrence and form throughout (the prefix "homo" means the same). Solutions consist of particles as tiny as fragments or molecules. For instance, a sugar solution is homogeneous because only transparent liquids can be seen. Homogeneous mixtures only have individual phase: gas, liquid or solid.
Solvent: normally the material in the greater amount. The material used to dissolve the solute or solutes. Example: water.
Solute: ordinarily the substance in the lesser amount. The substance dissolved by the solvent. Example: salt
Salt and water solution is homogeneous because only transparent liquids can be seen.
<span>Balanced nuclear reaction: 234/91 Pa → 4/2 He + 230/89 Ac.
1) number of protons and neutrons on both side of nuclear reaction must be the same. There are 91 protons (atomic number) and 143 neutrons (mass number - atomic number, 234 - 91 = 143 or (4-2) + (230 - 89) = 143)) on both side of reaction.
2) a</span>lpha
decay is radioactive decay<span> in which
an atomic nucleus emits
an alpha particle (helium
nucleus) and transforms into an atom with an atomic
number that is reduced by two and mass number that is reduced by four, so atomic mass of new element is 89 (91 - 2) and mass number is 230 (234 - 4 = 230).
3) look at atomic number, element with atomic number 89 is actinium.</span>
Answer:
81 molecules
Explanation:
The reaction between C5H12 and O2 is a combustion reaction and is represented by the following equation;
C5H12 + 8O2 --> 5CO2 + 6H2O
The ratio of C5H12 to O2 from the above equation is 1 : 8.
Aplying the conditins of the question; 24 molecules each of C5H12 and O2 we have;
3C5H12 + 24O2 --> 15CO2 + 18H2O
This means we have 24 - 3 = 21 molecules of C5H12 that are unreacted.
Total molecules is given as;
3(C5H12) + 24(O2) + 15(CO2) + 18(H2O) + 21(Unreacted C5H12) = 81 molecules
