Definition: The lightest chemical element (symbol H), with an atomic number of 1 and atomic weight of 1.00794.

Alright class, settle down, let’s take a look! Today we’re diving into something quite grand, A building block of matter, across the land! We're talking about hydrogen , a name you see, Let’s break it down for you and me! The dictionary gave us a helpful clue, "The lightest chemical element, it’s true!" (Symbol H – remember that, it's quick and neat!) Now, what does “lightest” truly mean? It’s the simplest atom, a wonderful scene! With an atomic number of one you find, The smallest element of any kind. And its atomic weight , a number so small, Just 1.00794 - standing tall! That tells us about its mass, you see, A tiny bit of hydrogen, happy and free! Think of it like this: Hydrogen is the start, The very first element, playing a part. In stars and water, it’s everywhere you roam, So remember hydrogen – a wonderful home! Any questions so far? Don't be shy, let’s explore!