Class 9 Science consists of Physics, Chemistry, and Biology. It is important for students to understand all the concepts available in these subjects to score well. Through these, students will be able to get solutions for questions that they get stuck in.
What is a solution Class 9 science?
A solution is a homogenous mixture comprising two or more components. In a solution the substance dissolved is the solute and the medium in which the solute is dissolved is called solvent.
How do we fall ill notes?
Immediate cause: The organisms that enter our body and causes disease is called immediate cause. For example, virus, bacteria, protozoa etc. surroundings, contaminated food, improper nourishment, poverty, poor standard of living etc. Diseases may be due to infectious and non-infectious causes.
Who discovered cell and how class 9?
Answer- Cell was discovered by an English Botanist, Robert Hooke in 1665. He used self-designed microscope to observe cells in a cork slice back then.
Why do we fall ill?
Answer: This is because the immune system of our body is normally fighting off microbes. Our body have cells that are specialised in killing infecting microbes. Whenever any microbes or foreign body enters our system, these cells become active and kill the microbes that could cause any damage to the body.
What is Tyndall effect class 9?
What is the Tyndall Effect? The Tyndall effect is the phenomenon in which the particles in a colloid scatter the beams of light that are directed at them. This effect is exhibited by all colloidal solutions and some very fine suspensions. Therefore, it can be used to verify if a given solution is a colloid.
Where can I get best notes for class 9?
INNOVATIVE GYAN provides the best All Subject Class 9 Notes in Hindi And English free for students to refer and score well in the class 9 CBSE Board exams.
What is an atom Class 9?
Explanation: An atom is the smallest unit of an element. In an atom, subatomic particles like protons and neutrons are present inside the nucleus and negatively charged electrons are present in the extranuclear part.
What is density Class 9?
Density Definition: Density is the measurement of how tightly a material is packed together. It is defined as the mass per unit volume. Density Symbol: D or ρ Density Formula: ρ = m/V, where ρ is the density, m is the mass of the object and V is the volume of the object.
Why do we fall ill Class 9 notes PPT?
i) Through air :- Common cod, Tuberculosis, Pneumonia etc. ii) Through water :- Cholera, Amoebic dysentry etc. iii) Through vectors :- Mosquitoes :- Malaria, Dengue, Yellow fever etc. Flies :- Typhoid, Tuberculosis, Diarrhoea, Dysentry etc.
What causes wind class 9?
Answer: Winds are caused due to unequal heating of atmospheric air. This phenomena can be easily seen near coastal regions during the daytime. The air above the land gets heated faster and starts rising. As this air rises, a region Of low pressure is created and air over the sea moves into this area Of low pressure.
Who discovered dead cell?
Robert Hooke discovers dead cells using early microscope.
Who discovered microscope?
Answer: Hans and Zacharias Janssen, 1590, who were spectacle makers in dutch designed the first simple microscope by placing two lenses of different power at the end of a tube. They could observe the enlargement of minute particles through the tube.
Who discovered cell first?
Initially discovered by Robert Hooke in 1665, the cell has a rich and interesting history that has ultimately given way to many of today’s scientific advancements.
What does disease look like?
Note: Disease can be viewed by examining symptoms of disease. The common symptoms of diseases include headache, fever, vomiting etc. Like jaundice can be examined by pale skin. Diarrhoea can be examined by loose motions.
What is vaccination Class 9?
Vaccination is the injection of a dead or weakened organism that forms immunity against that organism in the body. Immunization is the process by which an animal or a person stays protected from diseases.
What is difference between health and disease?
Hint: Health is defined as an individual’s mental, physical, and psychological well-being. The disease is defined as the abnormal dysfunctioning of the mental-physical states, which results in illness in a specific individual and does not take into account society or community.
Is milk a colloid?
Yes, milk is a colloid. It contains tiny globs of butterfat. These fats are suspended throughout the liquid.
What is meant by zeta potential?
Zeta potential is a physical property which is exhibited by any particle in suspension, macromolecule or material surface. It can be used to optimize the formulations of suspensions, emulsions and protein solutions, predict interactions with surfaces, and optimise the formation of films and coatings.
What is Sol and gel give example?
Sol is a solid dispersed in a liquid. Examples include Au, As2S3, S in water, paints, milk of magnesia. Gel is a liquid dispersed in solid. Examples include cheese, butter, jellies.
How do you self study for class 9?
- Except for Mathematics, study all other subjects for 1-1.5 hours each on a daily basis.
- Mathematics requires a lot of practice, so allocate 2-2.5 hours for Maths.
- Allocate 1.5 hours for Science.
- Similarly, allocate 1.5 hours for Social Science papers (History, Geography, Civics, etc).
Is Class 9 English easy?
Class 9th English is not so difficult if understood thoroughly.
How do you make a 9th class note?
- Step-I Survey the passage or text: Read the text with a bird’s eye view so that you can quickly find out what the passage is about and what the writer’s main ideas are.
- Step-2 Read the text again: Read the text quickly.
- Step-3 Write in a form: If you write the main points in a notebook.
What is a valency class 9?
Valency is simply equal to the number of electrons gained, lost or shared by an atom of an element to achieve the nearest noble gas configuration. For example, the valency of sodium (Na) is 1, magnesium (Mg) is 2, Chlorine (Cl) is 1 etc.
What is the smallest unit of matter?
The structure of the atom. An atom is the smallest unit of matter that retains all of the chemical properties of an element.