Question

given only the information from the periodic table entry shown below and the fact that the atom is neutral, choose all of the following that are true about a silicon atom. it has 14 protons. it has 14 electrons. it has 14 neutrons. each atom weighs 28.09 g

Explanation:

• Protons: The atomic number (14) of silicon (\(Si\)) indicates the number of protons in a neutral atom. So, it has 14 protons.
• Electrons: In a neutral atom, the number of electrons equals the number of protons. Since there are 14 protons, there are 14 electrons.
• Neutrons: The mass number (approximate \(28\)) minus the atomic number (\(14\)) gives the number of neutrons (\(28 - 14=14\), but the atomic mass is \(28.09\), which is an average of isotopes. We can't be sure from the given info (only atomic number \(14\) and atomic mass \(28.09\)) that there are exactly 14 neutrons.
• Mass per atom: The atomic mass (\(28.09\)) is the average atomic mass (in atomic mass units, \(u\)), not the mass of each atom in grams.

Answer:

It has 14 protons, It has 14 electrons.