Answer:
protons but different number of neutrons.
Explanation:
Answer: 6.022x10²³ (Avogadro's Number)
Explanation: The number of particles in 1 mole of a substance is determined by the Avogadro's Number.
The answer is C) reactants because a chemical reaction is the process in which atoms present in the starting substance rearrange to give new chemical combinations present in the substance formed by the reaction
The correct answer is:
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" F and Br , because they are in the same group" .
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Note:
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Choice [B]: "F and Br ; because they are in the same period" ; is incorrect; since "F" and "Br" are not in the same "period" (that is, "row").
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Choice [C]: "Na and Mg; because they are in the same group {"column"} ; is incorrect; since: "Na" and "Mg are NOT in the same group {"column"].
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Choice [D]: "Na and Mg" ; because they are in the same period {"row"}; is incorrect. Note: "Na" and "Mg" are, in fact, in the same period {"row"}. However, as aforementioned, {Mg and Na} are not in the same group {"column".}.
Note: The similiarities in physical and chemistry properties among elements are determined and organized — or tend to be so—by "groups" {"columns"} — NOT by "periods" {rows}.
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<span>the elements in groups1a, 2a, 3a have positive charges according to their group numbers</span>
