I. Answer the questions

1) How many chemical elements are there now?                                                                   

2) What is the symbol of Manganese?

3) What is a symbol usually derived from?

4) What does a subscript show?

5) What element is always designated first in the formula?

6) When did Mendeleyev discover the periodic law?

7) How can the Periodic Law be simply stated?

8) What elements were discovered after Mendeleyev modified the table?

9) Give some examples of polyatomic molecules of single elements.

10)What are simple diatomic molecules of a single element designated by?

 

II. True or false?

1) Symbols and formulas are used to indicate chemical reactions.

2) Groups of symbols are called equations.

3) Groups of symbols are called formulas.

4) The more electropositive element is always designated last in the formula.

5) Subscriptions are used to designate the number of atoms of each element present in the molecule.

6) Mendeleyev made his discovery in 1879.

7) There were several vacant spaces in Mendeleyev’s table which led him to predict the existence of six undiscovered elements.

8) The table wasn’t modified.

9) Properties of the elements are periodic functions of the nuclear charges of their atoms.

 

III. III. Identify the words, each dash stands for one letter only. Translate the words from exercise III and make up your own sentences with them.

1) d _ _ _ _ _ 2) _ y _ _ _ _ 3) _ _ sig _ _ _ _ 4) _ _ com _ _ _ _ 5) _ _ lya _ _ _ _ _ 6) _ _ _ _ _ ar 7) _ t _ t _ 8) v _ _ _ _ t	9) ex _ _ _ _ _ 10) arr _ _ _ _ _ _ _ _ 11) _ _ _ _ _ _ tion 12) m _ss _ _ g 13) var _ _ _ _ 14) _ _ _ _ fy 15) f _ _ _ tion
IV. Find special words and terms in the cross-word puzzle.	H Y D R O G E N P O R E A C P E L E N L E M C T E C T G E Y L E O I R O R Y M A E N P O I N E X U T C T P N O Y D O I O H Y E R D T I E L M E T I C I R X H C I M P R O P E O I D E I C A L V A L E N C

 

Unit 3. Rules of reading formulas and equations.

Обозначение и название важнейших химических элементов (к таблице Менделеева)

Al — aluminium  алюминий Ag — argentum серебро Ar — argon аргон As — arsenic мышьяк Au — aurum = gold золото B  — boronбор Ba — bariumбарий Be — berillium бериллий Bi — bismuth висмут Br — bromineбром C —carbonуглерод Ca — calciumкальций Ce — ceriumцерий Cd — cadmiumкадмий Cl — chlorineхлор Co —cobaltкобальт Cr — chromiumхром Cs —caesium цезий Cu — copper медь F — fluorineфтор Fe — ferrum = ironжелезо Ge — germanium германий H — hydrogen водород He — helium гелий Hg — hydrargyrum = mercuryртуть J —iodine йод Ir — iridium иридий K — kalium = po­tassium калий

Li —lithiumлитий Mg —magnesium  магний Mn — manganese марганец Mo — molybdenum молибден N — nitrogen азот Na — natrium = sodium натрий Ne — neonнеон Ni —nickel никель O — oxygen  кислород P — phosphorus фосфор Pb — plumbum = lead  cdbytw Pt —platinumплатина Ra —radium радий Rb —rubidium рубидий S — sulphur cepa Sb —antimony сурьма Se —seleniumселен Si — silicon кремний Sn — stannum = tin олово Sr — strontiumстронций Te — tellurium теллур Th — thorium торий Ti —titaniumтитан U —uranium уран W —wolfram = tungstenвольфрам Zn —zinc цинк Zr — zirconiumцирконий

Правила чтения химических формул

Буквы латинского алфавита, обозначающие название элементов, читаются согласно английским названиям букв алфавита.

Знак + читается plus, and, together, with, react with.

Знак — обозначает одну связь или единицу родства и не читается.

Знак = читается give, form или produce.

Знак →читается give, pass over to lead to.

Знак ↔ читается forms and is formed from.

Цифра перед названием элемента обозначаeт число молекул.

Примеры:

C + O₂ → CO₂

1 atom of carbon reacts with 1 two-atom molecule of oxygen and produces 1 molecule of carbon dioxide.

2H₂ + O₂ → 2H₂O

Two molecules of H two plus O two give two molecules of H two O.

или Two two-atom molecules of hydrogen react with 1 two-atom molecule of oxygen and produce two molecules of water.

N₂ + 3H₂ ↔ 2NH₃

N two plus three molecules of H two form and are for­med from two molecules of NH three

или 1 two-atom molecule of nitrogen plus three two-atom molecules of hydrogen form and are formed from two mole­cules of ammonia.

Na₂CO₃ + CaSO₄ → Na₂SO₄ + CaCO₃

Na two CO three plus CaSO four form Na two SO four plus CaCO three

или The sodium (Na) and the calcium (Ca) switch places. The sodium combines with the sulphate radical (SO₄), form­ing sodium sulphate (Na₂SO₄) which dissolves in water. The calciurrrrombines with the carbonate radical (CO₃), forming calcium carbonate (CaCO₃). Calcium carbonate does not dissolve in water, and so settles to the bottom of the solu­tion.

 

Task: - write any 20 formulas and read them

      - write any 5 equations and read them

Unit 4. Laboratory equipment.