Question

which element glows red when electricity flows through it?
a carbon
b iron
c hydrogen
d neon

Explanation:

Neon is a noble gas. When electricity is passed through neon gas (in a neon - filled tube), it emits a red - orange glow. Carbon is a solid non - metal and does not glow in this way when electricity is passed through it (in a typical sense). Iron is a metal and its electrical conduction properties are different from gas - based glow phenomena. Hydrogen gas, when ionized, has different spectral emissions (not typically a red glow like neon in common electrical discharge applications).

Answer:

d. neon