Hygrometer

Okay kiddo, have you ever seen the small device that shows you the humidity level in a room or a garden? That's called a hygrometer! It's like a little helper that tells you how much moisture is in the air.

You see, the air around us can have different amounts of water in it. Sometimes it's really dry and sometimes it's really wet. The hygrometer measures the amount of water vapor in the air and tells you if the air is dry, humid or just right.

Now, the hygrometer works by using a tiny, special material inside that can absorb or release water depending on the humidity. This material is called a "hygroscopic substance." When it absorbs moisture, it changes shape or size a little bit, and the hygrometer measures that change to tell you the humidity level.

So, when you see a hygrometer, just remember that it's like a little helper that shows how much water is in the air. It uses a special material inside to measure the humidity and tell you if it's dry, humid, or just right.