Answer:
In summary, work is done when a force acts upon an object to cause a displacement. Three quantities must be known in order to calculate the amount of work. Those three quantities are force, displacement and the angle between the force and the displacement.
An ionic bond is a type of chemical bond formed through an electrostatic attraction between two oppositely charged ions. Ionic bonds are formed between a cation, which is usually a metal, and an anion, which is usually a nonmetal. A covalent bond involves a pair of electrons being shared between at
Answer:
hydrogen bonds between water molecules
Explanation:
The hydrogen bonds between water molecules conditions the bulk of its physical property most especially its relatively high boiling point. The hydrogen bond results from the attraction between the oxygen of a water molecule and the hydrogen of another water molecule. The more electronegative oxygen atom causes a distortion and the attraction leads to a strong intermolecular bond between atoms of the water molecules.
Hydrogen bond is a very strong bond and it is responsible for the physical properties of water.
Answer : The amount of formaldehyde permissible are, 
Explanation : Given,
Density of air =

First we have to calculate the mass of air.



Now we have to calculate the amount of formaldehyde.
Permissible exposure level of formaldehyde = 0.75 ppm = 
Amount of formaldehyde in 7.2 g of formaldehyde = 
Amount of formaldehyde in 7.2 g of formaldehyde = 
Thus, the amount of formaldehyde permissible are, 
Answer:
I would say A
Explanation:
our ancestors are the people that lived long before us