Water, the amazing molecule

How many elements made the water molecule?

• 2.5

• 3

• 2

• 4

Why do we say that water is a polar molecule?

• Because is from the North Pole, so is polar

• The Oxygen side of the molecule is slightly negative, and the Hydrogen part is slightly positive

• Polarity refers to the same charges that repel

• The electrons are positive and the protons are negative

What is the charge of a proton and where is located in the atom?

• Negative, around the nucleus of the atom

• Positive and is part of the nucleus of the atom

• Negative is inside the nucleus of the atom

• Positive, around the nucleus of the atom

It is important to understand that Oxygen in the water molecule gets more electrons (-), and hydrogen gets less electrons so it is (+). In one word this refers to what property of water?:

• Negativity

• Positivism

• Polarity

• Neutrality

What is a covalent bond?

• Covalent means that the electrons are shared between 2 or more atoms

• Covalent means that the water molecule is ionic

• Covalent means that a compound is neutral

What is the name of the bond (or attraction) of one water molecule to another and is responsible for the water surface tension?

• Covalent bond

• Adhesion

• Hydrogen bond

• Cohesion

What is cohesion?

Choose all the answers you think are right

• Union or close relationship between people or things

• The union between the water molecules, due to the polarity of the water molecules

• when water molecules stick to each other

• When water molecules adhere to other substances

EXPERIMENT:

The hydrogen bonds between millions of water molecules create the surface tension. Some insects and objects kind of float, do not break the water surface tension, others just sink.

1.Take a glass and fill it with water

2. Take at least 5 paper clips.

3. Try to make the paper clip float, if you can...

You only have 5 attempts.

EXPLAIN: Why the paper clips sink or float?


Advice: put the paper clip gently over the water

EXTRA POINTS:

Explain with your own scientific words, why we sweat?

How many atoms form the molecule of water or H2O?

• 3.5

• 4

• 3

• 2