Answer:
Where SiO2 has strong covalent bonds between molecules, SO3 only has weak van der waals intermolecular forces holding its molecules together. Since covalent bonds require more energy to overcome than van der waals, SiO2 requires a higher temperature than SO3 to melt, thus SiO2 has a higher melting point.
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.
#1
Heterogenous mixture mean unsimilar substances .
- Chicken noodle soyp.
- salt water
- propane.
#2
An element is a substance made of only one type of atoms
Hey there!:
Molar mass MgCl2 = 95.2110 g/mol
So:
1 mole MgCl2 -------------- 95.2110 g
moles MgCl2 ---------------- 319 g
moles MgCl2 = 319 * 1 / 95.2110
moles MgCl2 = 319 / 95.2110
=> 3.350 moles of MgCl2
Hope that helps!