Answer:
Electrostatic Van de Waals forces act between molecules to form weak bonds. The types of Van der Waals forces, strongest to weakest, are dipole-dipole forces, dipole-induced dipole forces and the London dispersion forces. The hydrogen bond is based on a type of dipole-dipole force that is especially powerful. These forces help determine the physical characteristics of materials.
Answer:
The speed of light is the speed at which light travels. No, an object cannot move at the speed of light.
Explanation:
The speed of light is 186,000 miles per second. An object with mass cannot move at the speed of light since it would take an infinite amount of energy to achieve that velocity, since only massless particles can travel at the speed of light. Also, you would have to factor in air friction, meaning even if an object were to reach such high speeds, it would instantly disintegrate.
Answer:
Total mass of the reactant = 2+2.5 =4.5 mg
Total mass of product = 4.15 mg
therefore, mass of unreacted oxygen = 4.50-4.15 = 0.35 g
Answer:- 14.9 M
Solution:- Given commercial sample of ammonia is 28% by mass. Let's say we have 100 grams of the sample. Then mass of ammonia would be 28 grams.
Density of the solution is given as 0.90 grams per mL.
From the mass and density we could calculate the volume of the solution as:

= 111 mL
Let's convert the volume from mL to L as molarity is moles of solute per liter of solution.
= 0.111 L
Now, we convert grams of ammonia to moles on dividing the grams by molar mass. Molar mass of ammonia is 17 gram per mole.

= 1.65 mole
To calculate the molarity we divide the moles of ammonia by the liters of solution:

= 14.9 M
So, the molarity of the given commercial sample of ammonia is 14.9 M.