The average density of normal matter in the universe is \(4 \times 10^{-28} \mathrm{kg} / \mathrm{m}^{3} .\) The mass of a hydrogen atom is \(1.66 \times 10^{-27} \mathrm{kg}\) On average, how many hydrogen atoms are there in each cubic meter in the universe?

The term 'average density' refers to the amount of matter within a given volume. In this context, we are looking at the density of normal matter in the universe. The density is given as \(4 \times 10^{-28} \text{ kg/m}^3\). To better understand, think of density as how much 'stuff' is packed into a space. The universe is vast and mostly empty, so even this small number has significant implications.
Average density tells us how spread out the matter is across the universe. It's the key figure we use to understand how many particles, in this case, hydrogen atoms, are in a unit volume of space, like one cubic meter. The given density is vital for calculating the number of hydrogen atoms.

Hydrogen atoms are the simplest and most abundant elements in the universe. Each hydrogen atom has one proton, one electron, and no neutrons (in its most common form). Since hydrogen is the building block for more complex matter, estimating its presence gives us a good understanding of the matter in the universe.
When determining the number of hydrogen atoms in a cubic meter of space, we use density. By knowing the mass of a hydrogen atom, we can perform calculations to see how many such atoms would, on average, occupy one cubic meter of space.

The mass of a hydrogen atom is \(1.66 \times 10^{-27} \text{ kg}\). This small mass is crucial for many calculations in both chemistry and physics, especially when dealing with cosmic scales. Despite its tiny mass, knowing the exact value allows us to convert densities into quantities of atoms.
In calculating the number of hydrogen atoms, we compare the average density of matter with the mass of a single hydrogen atom. This comparison provides us with a useful ratio that tells us how many hydrogen atoms fit into a given volume.

A cubic meter is a volume measurement that is 1 meter tall, 1 meter wide, and 1 meter deep. This unit is essential for calculating densities and understanding the distribution of matter. When we refer to the number of hydrogen atoms per cubic meter, we are looking at this specific volume to see how many atoms fit within.
Using cubic meters makes it possible to scale these calculations up or down, maintaining consistent units when considering much larger or smaller volumes. For any volume calculations involving density, specifying the unit (like cubic meter) is necessary for clarity and accuracy.