Question

For each of the following elements, write its chemical symbol, locate it in the periodic table, give its atomic number, and indicate whether it is a metal, metalloid, or nonmetal: (a) chromium, (b) helium, (c) phosphorus, (d) zinc, (e) magnesium, (f) bromine, (g) arsenic.

Short answer

(a) Chromium: Cr, group 6 period 4, atomic number 24, metal. (b) Helium: He, group 18 period 1, atomic number 2, nonmetal. (c) Phosphorus: P, group 15 period 3, atomic number 15, nonmetal. (d) Zinc: Zn, group 12 period 4, atomic number 30, metal. (e) Magnesium: Mg, group 2 period 3, atomic number 12, metal. (f) Bromine: Br, group 17 period 4, atomic number 35, nonmetal. (g) Arsenic: As, group 15 period 4, atomic number 33, metalloid.

Step-by-step solution

Locate the element in the periodic table

Using a periodic table, we can locate the position of the element.

Write the chemical symbol

The chemical symbol is usually represented by one or two letters. The first letter is always capitalized, and the second letter, if present, is lowercase.

Find the atomic number

The atomic number is the number of protons in an atom's nucleus. It is typically found above the chemical symbol in the periodic table.

Determine if the element is a metal, metalloid, or nonmetal

Metals are typically found on the left side of the periodic table, nonmetals on the right, and metalloids between metals and nonmetals. Now, let's provide the information for each of the given elements: (a) Chromium (Cr) - Step 1: Located in group 6, period 4. - Step 2: Chemical symbol: Cr - Step 3: Atomic number: 24 - Step 4: Metal (b) Helium (He) - Step 1: Located in group 18, period 1. - Step 2: Chemical symbol: He - Step 3: Atomic number: 2 - Step 4: Nonmetal (c) Phosphorus (P) - Step 1: Located in group 15, period 3. - Step 2: Chemical symbol: P - Step 3: Atomic number: 15 - Step 4: Nonmetal (d) Zinc (Zn) - Step 1: Located in group 12, period 4. - Step 2: Chemical symbol: Zn - Step 3: Atomic number: 30 - Step 4: Metal (e) Magnesium (Mg) - Step 1: Located in group 2, period 3. - Step 2: Chemical symbol: Mg - Step 3: Atomic number: 12 - Step 4: Metal (f) Bromine (Br) - Step 1: Located in group 17, period 4. - Step 2: Chemical symbol: Br - Step 3: Atomic number: 35 - Step 4: Nonmetal (g) Arsenic (As) - Step 1: Located in group 15, period 4. - Step 2: Chemical symbol: As - Step 3: Atomic number: 33 - Step 4: Metalloid