Question

Use the portion of the periodic table shown below to answer the questions.

Part 1: Name two elements that have the same properties as calcium (Ca). (4 points)

Part 2: Determine the number of protons, electrons, and neutrons present in an atom of sodium (Na). Explain how you determined your answer using complete sentences. (6 points)

A portion of the first three columns of the periodic table is shown. Column one from top to bottom reads 11 sodium 22.990, 19 potassium 39.098, and 37 rubidium 85.468. Column two reads 12 magnesium 24.305, 20 calcium 40.078, and 38 strontium 87.62. Column three reads 21 scandium 44.956 and 39 yttrium 88.906.

Answer 1

Part 1: Elements with Properties Similar to Calcium

Two elements that have similar properties to calcium (Ca) are magnesium (Mg) and strontium (Sr). These elements belong to the same group in the periodic table, specifically Group 2 (alkaline earth metals). Elements in the same group often share similar chemical properties.

Part 2: Protons, Electrons, and Neutrons in Sodium (Na)

To determine the number of protons, electrons, and neutrons in an atom of sodium (Na), we look at the information provided in the periodic table excerpt. The number next to the element's symbol (Na) is its atomic number (11). This represents the number of protons in the nucleus of a sodium atom.

An atom of sodium (Na) has 11 protons, 11 electrons, and approximately 11 neutrons.