Test your knowledge with these top questions!
Which element gives many street lamps their orange glow?
These lamps use very little energy, which is why cities long used them for streets.
Which element uses the chemical symbol Na?
The symbol Na comes from natrium, an old Latin name for sodium compounds.
What happens when pure sodium metal touches water?
Sodium is stored in oil because even moisture in the air can trigger this reaction.
Which description fits pure sodium metal at room temperature?
Freshly cut sodium looks shiny but tarnishes within seconds when exposed to air.
Sodium ions help nerve cells transmit what?
Sodium ions crossing nerve-cell membranes change voltage, helping an electrical impulse travel along the cell.
Which isotope accounts for potassium's natural radioactivity?
Potassium-40 makes up a tiny natural fraction of potassium and decays radioactively, contributing to background radiation.
What color does freshly exposed cesium metal appear?
Cesium's unusual golden tint fades quickly as the reactive metal tarnishes in air.
Sodium's symbol, Na, comes from which Latin name?
Sodium's two-letter symbol reflects a Latinized name, while the English word comes from soda.
Which ion does lithium usually form in chemical compounds?
Lithium has one valence electron and normally loses it, producing the stable Li+ ion.
How does lithium behave in room-temperature water?
Lithium is less dense than water, so it floats while its reaction releases hydrogen bubbles that cause fizzing.