Strontium

Properties
Strontium is a chemical element with the chemical symbol Sr. It has the atomic number 38.

Strontium has 38 protons and electrons. Strontium has a mass number of 88, giving a strontium atom 50 neutrons. It is a silver-colored metal in the Alkaline Earth Metals group, however, exposing it to air can turn it yellowish in color. Strontium has a melting point of 777 oC and a boiling point of 1 377 oC.

Flame Test
Strontium and its compounds give a red coloration in the Flame Test, as seen in this picture:

Thus, Strontium compounds are used in red fireworks.