The octet rule is a chemical rule of thumb that reflects observation that atoms of main-group elements tend to combine in such a way that each atom has eight electrons in its valence shell, giving it the same electronic configuration as a noble gas. The rule is especially applicable to carbon, nitrogen, oxygen, and the halogens, but also to metals such as sodium or magnesium.
The valence electrons can be counted using a Lewis electron dot diagram as shown at the right for carbon dioxide. The electrons shared by the two atoms in a covalent bond are counted twice, once for each atom. In carbon dioxide each oxygen shares four electrons with the central carbon, two (shown in red) from the oxygen itself and two (shown in black) from the carbon. All four of these electrons are counted in both the carbon octet and the oxygen octet.
Answer:
160.3g
Explanation:
We know the equation:
No of moles = mass ÷ Mass of element
We need to find the mass, so make mass the subject of the formula.
Mass = No. of moles × mass of element
Mass = 5 × 32.06
Mass = 160.3g
Most chemical elements are solid at room temperature. Some elements exist as gases but only two elements, mercury (Hg) and bromine (Br) are liquids at room temperature (approx 25oC). Hope this helped you!
