Answer:
Mass number can vary due to the fact that the number of neutrons can vary. Isotopes are named for their mass numbers. So, this element has 15 protons (atomic number), 15 electrons, and 16 neutrons (mass number minus atomic number). This isotope is phosphorus-31, which has atomic number 15.
Explanation:
Answer:
4.index fossils, intrusions, and cross-cutting relationships
Explanation:
There are various geologic features or phenomenon that determines the relative ages of rocks . This geologic features or events includes index fossils , intrusions, cross cutting relationship etc. Note relative ages of rock does not give the actual ages oft the rocks but instead compares the ages of these rocks. Knowing the relative ages of rocks, one can decipher which rock is older or which one is younger. The geologic features give details on the sequence of event that happens through the formation.
Like the principle of cross cutting relationship states that the geologic feature which cut across or intrudes another geologic feature is younger than it surrounding rock.
Index fossils are remains of organisms that are widely spread. The deposition of this remains can give the sequence for deposition of the surrounding rocks which these fossils are found.
Intrusions occurs when geologic features like plutons invades another rock body. Geologically, the plutons will be younger than the surrounding or host rock.
Cladodes<span> (also called cladophylls or phylloclades) are shoot systems in which leaves do not develop; rather, the stems become flattened and assume the photosynthetic </span>functions<span> of the plant. In asparagus ( Asparagus officinalis; Asparagaceae), the scales found on the asparagus spears are the true leaves.</span>
<span>D. ligaments.
</span>Tough connective tissue structures that hold bones together are known as ligaments
NOT:
A. tendons.
<span>B. smooth muscles. </span>
<span>C. striated muscles. </span>