A pure substance has a constant composition and cannot be separated into simpler substances by physical means. There are two types of pure substances: elements and compounds. Elements: are pure substances made up of only l type of atom. Atoms of the same element are identical in properties.
The puppies have different colored noses because of reccesive and dominant genotypes.
Genotypes are represented by letters, capital being dominant and lowercase being recessive.
For example, lets say t = pink nose and T = black nose.
If the parents have black noses, then they will pass on T genotypes.
But, they also have hidden pink nose genotypes.
These hidden genotypes are passed on to the puppies, one of the puppies gets more black nose genotypes.
If a puppy gets tt, they will have a pink nose.
If they get TT, they will have a black nose
If they get Tt, they will also have a black nose.
Because the black nose is dominant, its more likley for the puppies to end up with a black nose.
Answer:
nuclear energy is the cleanest and safest energy source we have available and i agree with this statement for following reasons:
1. Nuclear power is generated by a controlled chain reaction involving the splitting of atoms. A modern nuclear power plant uses the intense heat created by this reaction to heat water and create steam, which turns a turbine and generates electricity. Whereas a coal-fired plant heats water by burning coal, a nuclear plant heats it by splitting atoms. This process is called nuclear fission.
2. Nuclear fission, in simple terms, occurs when an atom splits in two, releasing a massive amount of energy and several subatomic particles called neutrons. These neutrons, in turn, hit and split other atoms, beginning and sustaining the chain reaction. Reactor operators control this reaction in a variety of ways and thus regulate the amount of heat generated and energy produced.
3. The raw fuel for this process is the metal uranium, which must be enriched before it can be used for producing energy in commercial reactors. Enrichment is necessary because mined uranium ore is around 99.3 percent uranium-238, which, in today’s commercial power plants, does not readily split upon exposure to neutrons from the fission chain reaction, and thus makes poor fuel. The other 0.7 percent of mined uranium is uranium-235, which makes excellent fuel. The number refers to the atomic mass, or the total mass of protons and neutrons that make up the atomic nucleus. This difference in mass of the same element makes them two different isotopes of uranium. The enrichment process consists essentially of increasing the percentage of uranium-235 by decreasing the percentage (via removal) of uranium-238.
<h3>i hope you find your answer..</h3>
B,speedof light>speed of sound
