18. a) The materials that are in contact. The two materials and the nature of their surfaces. ...
b) The force pushing the two surfaces together. Pushing the surfaces together causes the more of the asperities to come together and increases the surface area in contact with each other.
19. the quantity of motion of a moving body, measured as a product of its mass and velocity.
20. According to Newton's third law of motion, action force is equal to reaction but acts on two different bodies and in opposite directions. When a horse pushes the ground, the ground reacts and exerts a force on the horse in the forward direction. This force is able to overcome friction force of the cart and it moves.
21. The mass of an object is a measure of the object's inertial property, or the amount of matter it contains. The weight of an object is a measure of the force exerted on the object by gravity, or the force needed to support it. The pull of gravity on the earth gives an object a downward acceleration of about 9.8 m/s2.
22. R12. Mass is more fundamental because it is an intrinsic property of an object. Weight varies with location depending upon the acceleration due to gravity eg. for a mass m = 10kg on Earth it`s weight is W = mg = 10 x 10 = 100N.
Answer:
transition metals
Explanation:
they're the elements in yellow in the picture
Answer:
The fundamental principle involves the formation of equilibrium and separation into distillate and bottoms governed by the equilibrium composition curve , number of stages and the purity with which the distillate is required.
Explanation:
Distillation is a type of the separation process by physical means of a mixture on basis of its difference in boiling point or vapor pressure .
Where we can just heat the mixture and separate out the components i.e the component with lower boiling point will form vapor easily and can be later condensed whereas the component with higher boiling point will remain as residue.
In case of a distillation column the same principle is applied at different stages to separate multiple components .The stages are known as trays or plates . In general , there is a certain liquid on each of the plate, and the arrangements are made for the ascending vapors to pass through the liquid and make contact with it . The fundamental principle involves the formation of equilibrium and separation into distillate and bottoms governed by the equilibrium composition curve , number of stages and the purity with which the distillate is required.
Answer:
Choose the least electronegative atom other than H.
Explanation:
A Lewis structure consists of <em>terminal atoms</em> and one or more <em>central atoms</em>.
H can be <em>only a terminal atom</em> because it can form only one bond.
So the central atom must be either C or O.
The central atom is the less electronegative atom: C.
So, start the Lewis structure with a central C atom.
Then attach an O atom to get C-O.
Finally, attach the H atoms.
The condensed formula often gives you a clue where they go.
The formula CH₃OH implies that there are 3 H atoms on C and one on O.
The connectivity of the atoms is then as in the diagram below.
