Answer:

Explanation:
Atomic number : It is defined as the number of electrons or number of protons present in a neutral atom.
However, when we talk about the atomic number of the ion, it is not equal to the number of electrons as electron can be gained or loosed.
This is why, more appropriately, the number of the protons which are present in the nucleus of the atom is called the atomic number.
Thus, atomic number of phosphorus = 15
Mass number is the number of the entities present in the nucleus which is the equal to the sum of the number of protons and electrons.
Given, Mass number = 32
Thus, the symbol of the isotope is:-

<span>In a titration, the substance that is unknown and being identified is called analyte. A titration is where a known solution or concentration called the titrant is used to identify and measure an unknown substance which is the analyte.</span>
Phenolphthalein is often used as an indicator in acid–base titrations. For this application, it turns colorless in acidic solutions and pink in basic solutions. Phenolphthalein is slightly soluble in water and usually is dissolved in alcohols for use in experiments.
<span>The </span>abundance of a chemical element<span> is a measure of the </span>occurrence<span> of the </span>element<span> relative to all other elements in a given environment. Abundance is measured in one of three ways: by the </span>mass-fraction<span> (the same as weight fraction); by the </span>mole-fraction<span> (fraction of atoms by numerical count, or sometimes fraction of molecules in gases); or by the </span>volume-fraction<span>. Volume-fraction is a common abundance measure in mixed gases such as planetary atmospheres, and is similar in value to molecular mole-fraction for gas mixtures at relatively low densities and pressures, and </span>ideal gas<span> mixtures. Most abundance values in this article are given as mass-fractions.
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