Question

fill in the missing information:

symbol	atom or ion? (check all that apply)	number of protons	number of electrons
$\ce{sn}$	neutral atom, cation, anion	$\square$	$\square$
$\square$	neutral atom, cation, anion	35	36

Explanation:

For \( \boldsymbol{\text{Sn}} \) row:

Step1: Determine atom/ion type

Sn (tin) is a neutral atom (no charge shown), so check "neutral atom".

Step2: Find number of protons

The atomic number of Sn is 50, so number of protons = 50.

Step3: Find number of electrons

In a neutral atom, electrons = protons, so electrons = 50.

Step4: Determine symbol (already given as Sn)

For \( \boldsymbol{\text{B}^{2+}} \) row:

Step1: Determine atom/ion type

\( \text{B}^{2+} \) has a positive charge, so it's a cation (check "cation").

Step2: Find number of protons

Atomic number of B is 5, so protons = 5.

Step3: Find number of electrons

For a cation with charge \( +2 \), electrons = protons - charge = \( 5 - 2 = 3 \).

For the last row (symbol missing):

Step1: Determine atom/ion type

Protons = 35, electrons = 36. Since electrons > protons, it's an anion (check "anion").

Step2: Find symbol

Atomic number 35 is bromine (Br). As an anion, it's \( \text{Br}^- \) (since electrons = 36, protons = 35, charge = \( 35 - 36 = -1 \)).

Filled Table (rows from left to right, top to bottom):

Symbol	atom or ion? (check all that apply)	number of protons	number of electrons
Sn	neutral atom	50	50
\( \text{Br}^- \)	anion	35	36

Answer:

• \( \text{B}^{2+} \): cation, protons = 5, electrons = 3
• Sn: neutral atom, protons = 50, electrons = 50
• Missing symbol: \( \text{Br}^- \), anion, protons = 35, electrons = 36