Answer:
A glance of earth taken from space will depict it blue. This blue colour is actually water, the major part of the earth is covered with water. We need water for almost everything, for example- drinking, bathing, cooking etc and therefore we should know about the properties of water. 65 % human body is composed of water. Water is essential for the survival of life on earth. Water is distributed unevenly on the earth’s surface. It forms a major solvent and dissolves almost every polar solute. So let us have a look at its properties.
Physical properties of water : Water is a colourless and tasteless liquid. The molecules of water have extensive hydrogen bonds resulting in unusual properties in the condensed form. This also leads to high melting and boiling points. As compared to other liquids, water has a higher specific heat, thermal conductivity, surface tension, dipole moment etc. These properties form the reason for its significance in the biosphere. Water is an excellent solvent and therefore it helps in the transportation of ions and molecules required for metabolism. It has a high latent heat of vaporization which helps in the regulation of body temperature
Chemical properties of water: Amphoteric nature:
Water can act as both acid and base, which means that it is amphoteric in nature.
Example:
Acidic Behaviour: H2O(l)+NH3(aq) ⇌ H3O+(aq)+NH+4(aq)
Basic Behavior: H2O(l)+H2S(aq) ⇌ H3O+(aq)+HS−(aq)
Redox reactions:
Electropositive elements reduce water to hydrogen molecule. Thus water is a great source of hydrogen. Let us see an example in this case:
2H2O(l)+2Na(s)→2NaOH(aq)+H2(g)
During the process of photosynthesis, water is oxidized to O2. As water can be oxidized and reduced, it is very useful in redox reactions.
Hydrolysis reaction
Water has a very strong hydrating tendency due to its dielectric constant. It dissolves many ionic compounds. Some covalent and ionic compounds can be hydrolyzed in water.
Explanation:
Answer:
the penguins have a special care process since the hatching of the egg, the newborns receive care from their parents and have warmth from them placing themselves between their paws, the parents take turns caring for them and when the father is not with the chick, he goes in search of food, which he gives regurgitated, then the cris can go to a kindergarten where others of the same age are cared for by a herd of penguins, however his parents go to the sea and feed and continue to bring food to their son, this process it is kept until they change plumage and are ready to get their food on their own.
The studies are designed this way b/c it removes the power of suggestion and the double-blind study keeps both researchers and participants in the dark. So this compared to who is receiving the treatment which is relevant b/c it stops the researchers from accidentally overbalancing the study participants, or unintentionally favoring their assessment of the conclusions.
The correct options are, frying an egg and burning candle.
Explanation :
Physical change : It is a change in which no new compounds are formed only changes occurs in size or state of substance. In this, there is no changes in the substance or compound.
Chemical change : It is a change in which a new compounds are formed by the chemical reaction. Changes occurs in their chemical composition and properties.
Frying an egg : It is a chemical change because a new substance is form by heating.
Burning a candle : It is chemical change because new substances are formed (carbon dioxide, water and heat) by burning.
Boiling alcohol : It is physical change because only changes in the state.
Melting and ice : It is a physical change because only changes in the state.
Making coffee : It is a physical change because no new substance is formed.
Therefore, frying an egg and burning candle are the example of chemical change.
Answer:
Explanation:
The scientific method
Make an observation.
Ask a question.
Form a hypothesis, or testable explanation.
Make a prediction based on the hypothesis.
Test the prediction.
Iterate: use the results to make new hypotheses or predictions.
hope this helps
