How many atoms exist in the universe?

The universe is a vast range to consider and while knowing that all matter is composed of extremely small particles called atoms, it is estimated that there may be 10 78 to 10 82 atoms in the known universe.

How many atoms are present in a single molecule of Na2SO4?

A single molecule of Na 2 SO 4 contains 7 atoms. This includes 2 atoms of Sodium (Na), 1 atom of Sulfur (S), and 4 atoms of Oxygen (O).

How many atoms are present in a compound?

The number of atoms in a compound depends on its molecular formula. For example, in a molecule of water (H 2 O), there are 3 atoms - 2 hydrogen atoms and 1 oxygen atom. In a molecule of glucose (C 6 H 12 O 6 ), there are 24 atoms - 6 carbon atoms, 12 hydrogen atoms, and 6 oxygen atoms. So, you need to know the molecular formula of the compound to determine the number of atoms.

What is the radioactive element with the lowest atomic number?

The radioactive element with the lowest atomic number is Technetium with the atomic number of 43. It's the lightest element that has no stable isotopes. Every isotope of technetium is radioactive.

Is it possible for the atomic mass of an element to change?

Yes, the atomic mass of an element can change. This is because the atomic mass is not a fixed number, but an average of the masses of the different isotopes of an element. Isotopes are atoms of the same element that have different numbers of neutrons, and therefore different masses. If the abundance of these isotopes changes, the average atomic mass will also change. However, in nature, these proportions usually remain fairly constant, so the atomic mass of an element typically remains the same.