Look up the density of silicon and of lead in a table online. Then look up the atomic radius of silicon and lead . Then look up the atomic mass of each element (periodic table of elements). Use the atomic mass and atomic radius of each element to make an argument about density. Based on the atomic radii and atomic mass data, which element would be the most dense. Is that expectation consistent with actual density data? Use the definition of density to support your argument.

The densities of atoms depends on the number of protons in the nucleus. The number of protons is equal to the number of electrons. The electron cloud interaction, electronegativity of atom and noble gas configuration also affect the radius as well as the nuclear densities. Electron pair repulsion increases the atomic radius. Density Density of silicon is 2.33 g/cm3 (gram per centimeter cube) Density of lead is 10.67 g/cm3 Radius Radius of silicon 110 pm (picometer) Radius of lead is 180 pm Atomic mass Atomic mass of silicon is 28.08 u (unified atomic mass unit) Atomic mass of lead is 207.2 u Atomic number Silicon (Si) 14 Lead (Pb) 82 The density of an element is the measurement of the mass of total atoms in a specific volume. The nuclear density is made up of the protons and neutrons. Number of protons per unit radi gives the density of the atom. The density of each atom effects and correlates the density of the element. Theoretical observation Silicon has 28 u mass in 110 pm of radius, whereas Lead has 207 u in 180 pm length. Lead is denser than silicon. The atomic number of Silicon is 14 and that of lead is 82. Thus, 14 protons are there within 110 pm of radius, on the other side, lead has 82 protons in 180 pm. Actual densities observed The density of silicon is 2.33 g/cm3 and that of lead is 10.67 g/cm3 . Both of the observations are at par.