Question

karin compared four different elements.

boron	oxygen	beryllium	lithium
period 2	period 2	period 2	period 2
5 protons	8 protons	4 protons	3 protons
solid	gas	solid	solid

she studied the chart and found one element that has only one characteristic that is the same as any of the other elements. which element is it?
oxygen
beryllium
lithium
boron

Explanation:

Step1: Analyze Boron

Boron is a metalloid, in period 2, has 5 protons and is solid. It has the same period as the others. It has multiple common - characteristics with other elements.

Step2: Analyze Oxygen

Oxygen is a non - metal, in period 2, has 8 protons and is a gas. It has the same period as the others, but its state (gas) is different from most (solid), and its type (non - metal) is different from metals. It has only the period in common with others.

Step3: Analyze Beryllium

Beryllium is a metal, in period 2, has 4 protons and is solid. It has multiple common - characteristics (metal, period 2, solid) with other elements.

Step4: Analyze Lithium

Lithium is a metal, in period 2, has 3 protons and is solid. It has multiple common - characteristics (metal, period 2, solid) with other elements.

Answer:

Oxygen