A general rule doesn't exist.
In changes in which the molecular structure of a substance remains constant, such as changes of state, we often refer to these changes as Physical Changes. If the molecular structure is altered it would be a Chemical Change.
an amorphous substance is something that has a random molecular formation in it's natural form (when solidified). the opposite would be semi-cristaline which has random molecular structure when heated but returns to an organised unifom state when solidified. example. certain polymers
For an element, it would be an atom. For a molecular substance, it would be a molecule. If it is an ionic compound, it would be a formula unit.
For an element, it would be an atom. For a molecular substance, it would be a molecule. If it is an ionic compound, it would be a formula unit.
For an element, it would be an atom. For a molecular substance, it would be a molecule. If it is an ionic compound, it would be a formula unit.
For an element, it would be an atom. For a molecular substance, it would be a molecule. If it is an ionic compound, it would be a formula unit.
For an element, it would be an atom. For a molecular substance, it would be a molecule. If it is an ionic compound, it would be a formula unit.
If there is no reaction occuring to change the molecular structure of the substance, you have to look at the ionic product of the substance. When the ionic product is more than the Ksp of the substance, there would be precipitation of the substance
The mass in grams of a substance that equals one mole of that substance is the molecular weight of the substance, which can be found by adding the atomic weights of all the atoms in the molecule. For C2O2H4, the molecular weight would be (12 x 2) + (16 x 2) + (1 x 4) = 60 g/mol.
That's a very good question and there are arguments for both. I would class it more as a simple molecular substance because a sample will contain many separate molecules, with forces other than covalent bonds between them. A giant covalent structure like diamond is wholly held together by covalent bonds.
If C2H5 was the molecular formula its molecular mass would be 29 ( 12 x 2 + 5 x 1) However, 29 x 2 = 58 the actual molecular mass. So we double up the atoms in C2H5 to C4H10 . C4H10 is the molecular formula.
The substance would be in a liquid and gas state, this would be due to vaporization that is happening during boiling.