Where is the TM for Thunder in Pokemon Soul Silver?

Question

I need to teach my Lapras thunder for its moveset. Where can I find it or buy it? If I need to buy it, how much is it?

Comments

Wouldn't it be easier to go on serebii with all due respect to this community's swift answers?

Answer 1

You can buy them in the Goldenrod City Department store. It costs 5500P.

Source: My HeartGold game.