Answer:
A chemical element is a type of atom with the same number of protons in their <u>atomic</u> nuclei.
Explanation:
For an example, the atomic number of Chlorine is 17, and there is 17 protons in Chlorine.
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Answer:
Index fossils
Explanation:
The index fossils are the fossils that come in very handy for the geologists when it comes to identifying or dating rock samples or other fossils. The reason for this is that the index fossils have already been dated. They are fossils that are very commonly found, wide dispersed, are easy to be identified, and are limited to only a certain geological period. These characteristics make them an excellent indicator for the dating of the rock layers in which they are found, or the fossils found in the same layers with them, without conducting further examinations.
Answer:
A nucleotide consists of a sugar molecule (either ribose in RNA or deoxyribose in DNA) attached to a phosphate group and a nitrogen-containing base. The bases used in DNA are adenine (A), cytosine (C), guanine (G), and thymine (T).
Explanation:
