                                        HYDROGEN
               Let's start our tour with the element hydrogen (H). Why start with hydrogen?
             Hydrogen is the first element in the periodic table and the most basic and common
             of all elements in the Universe. Over ninety percent of all the atoms in the universe
             are hydrogen atoms, and they are the lightest of all elements.
               The name hydrogen comes from the Latin word "hydro", which means water
             (H2O), because water contains hydrogen atoms. Scientists use the letter "H" to
             represent hydrogen in chemistry.

Where can we find hydrogen?

             The sun
                  Hydrogen is very easy to burn. As you know, the Sun is one big ball of fire.
             One of the elements that make the sun burn so brightly is hydrogen.

Welding and Blowtorches
      Sometimes you can see someone working with a blowtorch, or welding
something together. They use gases that can burn very hot and make a bright flame.
One of those gases is hydrogen.

             Plants and Sugars
                  Hydrogen is in all plants. There are sugars all throughout plants and there is
             hydrogen in sugar. That's why animals eat plants- for the sugar and the energy.

Cryogenics
    Hydrogen is used in something called cryogenics. Cryogenics is a process
when scientists freeze things. When hydrogen is in a liquid form, it is very,
very cold. Scientists use this cold hydrogen to freeze things very quickly.




1. Match the word with the picture:

Burn

Blowtorch

Welding

Liquid

Freeze




2. True or false?


                                                               T/F

 Hydrogen is used to heat and freeze materials.

 Hydrogen is very heavy element.

 We can use hydrogen to weld metals together.

 All plants contain hydrogen.

 We have to be careful with hydrogen because it is easy to

 burn and can explode.

 Water contains hydrogen.




THE      NEXT   2                                      “PREPARATION
                    QUESTIONS ARE CONNECTED TO THE LAB WORK
AND PROPERTIES OF HYDROGEN” YOU DID IN THE PREVIOUS LESSON.



3. Hydrogen is prepared by reaction of 2 substances. Fill the names of these substances
(reactants) in the chemical equation:

………………………… + …………………………. → hydrogen + chloride solution

4. Describe the properties of hydrogen:


-state of matter (solid/liquid/gas)

-color

-odour (yes/no)

-density (light or heavy)

-typical reaction with element

-typical compounds

-explosiveness (can it explode?)

-flammability (can it burn?)


                                        HYDROGEN
               Let's start our tour with the element hydrogen (H). Why start with hydrogen?
             Hydrogen is the first element in the periodic table and the most basic and common
             of all elements in the Universe. Over ninety percent of all the atoms in the universe
             are hydrogen atoms, and they are the