How many protons and electrons are in each of the following ions? (a) Be2+

Verified step by step guidance

1. Step 1: Identify the atomic number of the element. The atomic number of an element is equal to the number of protons in its nucleus. For Beryllium (Be), the atomic number is 4. Therefore, Be has 4 protons.
2. Step 2: Determine the number of electrons. In a neutral atom, the number of electrons is equal to the number of protons. However, in an ion, the number of electrons can be different. The charge of an ion is determined by the difference between the number of protons and electrons.
3. Step 3: Calculate the number of electrons in the ion. Since Be2+ has a charge of +2, it means it has lost 2 electrons. Therefore, subtract the charge of the ion from the number of protons to find the number of electrons.
4. Step 4: In this case, Be2+ has 4 protons (from Step 1) and it has lost 2 electrons (from the charge), so it has 4 - 2 = 2 electrons.

Key Concepts

Atomic Structure

Atoms consist of protons, neutrons, and electrons. Protons are positively charged particles found in the nucleus, while electrons are negatively charged and orbit the nucleus. The number of protons defines the element, and in a neutral atom, the number of electrons equals the number of protons.

Ions

Ions are atoms or molecules that have gained or lost one or more electrons, resulting in a net charge. Cations are positively charged ions formed by losing electrons, while anions are negatively charged ions formed by gaining electrons. The charge of an ion indicates the difference between the number of protons and electrons.

Charge Calculation

To determine the number of protons and electrons in an ion, one must consider its charge. For example, a Be2+ ion has lost two electrons compared to its neutral state. Since beryllium (Be) has 4 protons, a Be2+ ion will have 4 protons and 2 electrons, reflecting its positive charge.