Chemistry lecture 14

Lecturer:D.Myagmarsuren

Translate the sentences into Mongolian

1.      As water evaporates, the movement of the water molecules become freer.

2.      A hot object is cools down to the temperature of the surroundings, but it never gets hotter than its environment.

3.      The important point is that an energy decrease in the system is one factor that favors spontaneity.

4.      If the reacting substances are at different states of matter, the state of subdivisions of solids affects the rate of the reaction.

5.      He rate at which a reaction occurs depends on the nature and physical states of reacting substances.

6.      A covalent bond consists of a mutual sharing of electron pairs between atoms.

7.      Atoms of metals tend to lose electrons to have the electron configurations of noble gases.

8.      Since the cooled gas is in contact with water, it will be saturated with water vapor.

9.      According to their physical and chemical properties, elements can be classified into three groups: metals, nonmetals and metalloids.

10.  The symbols are formed from one or two letters of the names of the elements.

11.  Electrolyte is a substance that conducts an electric current in solution.

12.  In combination reaction, two or more substances combine to form a single more complex compound.

13.  Carbon in the compound reacts with copper oxide to form carbon dioxide which turns limewater milky.

14.  More than five million organic compounds have already been synthesized from natural sources.

15.  Lewis structure is a structural formula drawn with Lewis symbols that show the valence electrons using dots.

16.  If the compound contains hydrogen, water is formed and it condenses in the cool portion of the tube.

17.  As the star contracts the temperature of the helium-rich core increases, and helium nuclei fuse to form carbon.

18.  When the reaction is complete, cool the reaction flask to room temperature.

19.  Dissolve 4.5 u of sodium acetate in 10 ml of water in beaker and warm the solution.

20.  Continue to stir the mixture for 20 min then cool it in an ice bath to complete crystallization. .

21.  When atoms combine to form compounds, they are held together in definite proportions by forces of attraction.