The atomic number (Z) uniquely identifies a chemical element. In an uncharged atom, the atomic number is also equal to the number of electrons.
The atomic number, Z, should not be confused with the mass number, A, which is the number of nucleons, the total number of protons and neutrons in the nucleus of an atom.
In this video Kristine Born explains this two concepts in more detail.
<h2>Answer:</h2>
Compound. Option A is correct
<h2>Explanations:</h2>
When two or more different elements combines, a compound is formed. For instance, if carbon and oxygen combines, carbondioxide is formed according to the equation;
From the reaction, carbon and oxygen are the elements while carbondioxide is the compound. Hence we can conclude that a pure substance formed when two or more different elements combine called compound.
Answer:
A and C
Explanation:
The term formula unit is use to indicate Simple-Whole Ratios of ions in a compound. KEY WORD! RATIO!
Condensation<span> is the process by which </span>water<span> vapor in the air is changed into liquid </span>water<span>. </span>Condensation<span> is crucial to the </span>water cycle<span> because it is responsible for the formation of clouds. ... </span>Condensation<span> is the opposite of evaporation.</span>
The correct answer for this question is this one: " a.The solution has a volume of 25 mL "
The observation that shows a quantitative observation is when you are talking about numeric data. Just like this one, <em>The solution has a volume of 25 mL </em>
Hope this helps answer your question and have a nice day ahead.