It’s c sun moon and earth line up with the moon in the middle
When an atomic nucleus emits an alpha particle it decay into an atom with atomic number 2 less and mass number 4 less. Thus Thorium 230 decay as follows.
230 90Th -------> 226 88Th + 4 2 He
thorium is in the atomic number 90 thus it during alpha decay it reduces to atomic number 88 while its 230 mass number reduces to 226
There are no lone pair of electrons shown around the hydrogen atoms, rather there are 2 lone election pairs present around the central atom in this Lewis structure and that is Oxygen. Hydrogen only has bonding electrons, and it requires 2 electrons per hydrogen to achieve stability and have a full valence electron shell.
<span>The atmosphere is a thin layer of gases that surrounds the Earth. It seals the planet and protects us from the vacuum of space. It protects us from electromagnetic radiation given off by the Sun and small objects flying through space such as meteoroids.</span><span>
So it's like a blanket protecting us but it has air hole/patches where sunlight can get through</span>