Molecular solidsâ Made up of atoms or molecules held together by London dispersion forces, dipole-dipole forces, or hydrogen bonds. Characterized by low melting points and flexibility and are poor conductors. An example of a molecular solid is sucrose.
There are two main problems when it comes to hard-boiled eggs: green-gray yolks and shells that just wonât peel off. Make hard-boiled eggs headache-free by following this easy method. First, place the cold eggs in a single layer in a pan with enough cold water to cover them by about 1 inch. Then, place the pan on the stove over high heat. Shutterstock. As soon as the water comes to a boil turn the heat off, cover the pan, and remove it from the heat. Allow the eggs to sit in the water until they are cooked; about 9 minutes for a medium egg, 12 minutes for a large egg, and 15 minutes for an extra-large egg.
1 If you want a hard-boiled egg, cook for 9 mins. 2  The shells are more fragile than hen eggs; to help avoid them cracking keep them at room temperature and lower them gently into the water with a slotted spoon. 3  Pricking the shell with a pin (being careful not to pierce the egg sac) can also help.