2. Structure of the water molecule.• Water molecule:• Two hydrogen and one oxygen atom
3. Properties of water • Dipole character of water molecules and the hydrogen bonds that form between them, determine the biological importance of water for living organisms.
4. Leva River• Leva is a river in northwestern of Bulgaria. Springs from Vratsa Mountain and continue to the bottom of the mountain. The river passes through the city Vratsa and flows into the Ogosta river.
5. Iskar River is locatedin western Bulgaria. It springs from the Rila Mountains and is the longest river in the country - 368 kilometers.
6. Catchment area of river Iskar
7. It rises in theShvartsvald in Germanyand flows into the Black Sea. We are bound by many countries in Europe. It shall carry out the links on our country with the countries of Western and Central Europe.
8. Danube region Black Sea Region
9. The river sore the main of thewater resources in Bulgaria .Relatively small area thecountrys proximity to the BlackSea and the Aegean, and thecomplex of geological andgeomorphologic features are thereason our country rivers areshort and with small averagerunoff .
10. Osam river is 314 km long and its catchment area is2,820 km ². It springs from the foot of Levski peak a part of the BalkanMountains at an altitude of1,821 m ,length of the river is 314 km to 2824 km catchment area.Osam formed by the merger of the Black Osam River, conditionally accepted forits home, and White Osam. It flows into the Danube near the town of Nikopol.
11. Wit was formed bythe merger of White and Black Wit. Wit river springs from the foot of peak Vejen (Balkan Mountains) at analtitude 2030 m .It is 189 km long.
12. Yantra is a river in northern Bulgaria. It springs from theBalkan Mountains and flows into the Danube. Its 285 km long and is the third largest among the Bulgarian Danube tributaries.
13. Ropotamo springs from the northeastern foot of the Strandja Mountain.It passes through the northeast Bulgaria after leaving Strandja andcontinues its way throughthe narrow gorge between the Copper Ridge and Uzundzhata hill and goesinto wide marshy valley toits mouth in the Black Sea. The length of the river is 48.5 km.
14. River in northeasternBulgaria, part of the Black Seadrainage area. Formed by the merger of two tributaries: Kamchia and great Kamchia who originate from the eastern part of the Balkan Mountains.
15. Maritsa River is the largest river on the Balkan Peninsula. Maritza is the mostwater river in Bulgaria. Tributaries of the Maritsa river are also Tunja and Arda, but because they coverhuge areas and run asindependent boundary rivers flow into the Maritsa Turkish territory, they are treated as separate
16. The largest tributary of the Maritsa Rive is Tundzha river. Due to the largearea of the catchment area (7884 km2), and because the border runs as a separate river, Tundzha is considered as a separate basin. It springs from thecentral part of the mountain east of Botev peak. Its length is 350 kilometers to the border.
17. Arda river is situated in southern Bulgaria andnortheastern Greece (named Ardas).It is about 300 km long (241 km on Bulgarian territory). Arda springs from Ardin peak in the Rhodopes and flows into the Maritzariver on Greek territory near Edirne.Arda River dams are Kardjali,Studen well and Ivaylovgrad.
18. Struma is a river situatedin southwestern Bulgaria. It springs from Vitosha.The length of the river onBulgarian territory is 290 km.
19. Runs through southwestern Bulgaria and in Greece. Formed by theconfluence of the rivers Black and White Mesta that spring from Rila mountain. For beginning of the river is accepted to be the group of Eastern Rila Lakes. The altitude of the Bulgarian part ofthe river is 1,318 m and with that Mesta is the highest valley in Bulgaria. The length of the riverto the border is 126 km. There are about 25 tributaries.
20. ВОДОСБОРЕН БАСЕЙН НА РЕКА МЕСТА
21. Sunset over Yantra Varbitsa River
22. Prepared by the students of IX grade , , Ni k ola Voyvodov ” Secondary school , Vratsa , Bulgaria