<span>An atom is composed of at least three types of subatomic particles. An electron has properties of both waves and particles. An atom is mostly empty space with a dense, positively charged nucleus.</span>
Answer:
7. 4H₂O
Elements: Hydrogen, Oxygen
Number of molecules: 4
Number of elements: 8 H, 4 O
Number of Atoms: 12
Explanation:
The elements are determined by the their symbol i.e. H = hydrogen.
The number of molecules is determined by the coefficient ( the number in front of everything, in this case 4).
The number of elements is determined by the coefficient and the subscripts. Multiply the coefficient by the subscript after each element. When there is no subscript, it is equal to 1. 4H₂ = 4x2 = 8; 4O = 4x1 = 4.
The number of atoms is all the individual elements added together. 8+4 = 12.
Answer:
a: chemical change because the change cannot be reversed.
b: physical change because the action can be reversed.
c: chemical change.
d:chemical change.
any change that cannot be reversed is a chemical change and any change that can be reversed is a physical change.
Answer:
Stronger
Greater
Higher
Explanation:
Molecules are held together by intermolecular forces. These are forces that act between molecules in a particular state matter. Intermolecular forces depend on the nature of the molecule.
For polar molecules, the intermolecular forces are stronger thus it takes more energy to separate them leading to a higher boiling point of polar molecules irrespective of their molecular mass.
