CBSE > Class 09 > Science | CBSE Board | Homework Help | myCBSEguide

No products in the cart.

Ask questions which are clear, concise and easy to understand.

Ask Question

What is division of labour? Explain it in context of multicellular organisms.

Posted by Abhishek Kumar Sinha 4 years ago

CBSE > Class 09 > Science

1 answers

Yogita Ingle 4 years ago

In unicellular organisms, the cell is capable of performing the different life processes with the help of the different cellular organelles. The division of labour in multicellular organisms refers to the presence of different organ systems that are incharge of taking care of a particular life process. For example, the respiratory system, helps the body in obtaining oxygen from the air and supplying it to the rest of the body.

ANSWER

What is the mast cell?

Posted by Jay Kushwaha 4 years ago

CBSE > Class 09 > Science

2 answers

Bhumika Sharma ✓ 4 years ago

Mast cells are long-lived tissue-resident cells with an important role in many inflammatory settings including host defence to parasitic infection and in allergic reactions..............nice to help u ☺️.

Kalpana Singh 4 years ago

A type of white blood cell that is found in connective tissues all through in body, especially under the skin, near blood vessels and lymph vessels, in nerves, and in the lungs and intestines. .... Mast cell are part of the body's immune system.

ANSWER

What is parabolic motion

Posted by Jatin Chauhan 4 years ago

CBSE > Class 09 > Science

1 answers

Lavishka Choudhary 4 years ago

Projectile motion is a form of motion experienced by an object or particle that is projected near the Earth's surface and moves along a curved path under the action of gravity only. This curved path was shown by Galileo to be a parabola, but may also be a line in the special case when it is thrown directly upwards.

ANSWER

Function of Areolar tissue

Posted by Jatin Chauhan 4 years ago

CBSE > Class 09 > Science

2 answers

Zoya . 4 years ago

Acts as a binding tissue. Bind the skin with muscles. Bind the blood vessels and nerves with other structures of body. Helps in healing of wounds.

Sujita N B 4 years ago

Areolar connective tissue is one of six forms of connective tissue within the body and is named after the airy appearance of the tissue. It is found surrounding blood vessels, nerve bundles, muscles, and organs. It also fills the spaces between organs and connects your skin to your underlying muscle.

ANSWER

A diver is able to cut through water un a swimming pool. which property of matter does this observation show?

Posted by Sharanpreet Singh Lubana 4 years ago

CBSE > Class 09 > Science

3 answers

Samruddhi Fukat 4 years ago

There is attraction between the particles of matter.

Kartikey Pandey 4 years ago

There is spaces present between particles of matter of liquid that is why a diver is able to cut throug wayer in a swimming pool

Ananya K 4 years ago

The driver is able to cut through water in a swimming pool. This observation shows that the matter has space between them so that the particles can move from one place to another accommodate the body of the driver.

ANSWER

Any body tell me why objects float and sink in water? explain

Posted by Roshani Pal 4 years ago

CBSE > Class 09 > Science

1 answers

Satakshi Mishra 4 years ago

Some objects float in water because they have less density than water whereas some objects sink in water because they have more density than water

ANSWER

How do we calculate valency???

Posted by Nanthithaa Varshini 4 years ago

CBSE > Class 09 > Science

2 answers

Ananya K 4 years ago

If the number of electrons in the outer shell is between 1 to 4 the compound is said to have positive valency. For compound with electrons 4,5,6, or 7 the valency is determined by subtracting the electrons from eight

Rashi Aastha 4 years ago

U can use electronic configuration Like in oxygen 2,6 which add up to 8 which is its atomic no. The general e.c. should be following 2,8,8 like that So it's missing two electrons So it will be -2

ANSWER

Wnat is osmosis

Posted by Gokul Settu 4 years ago

CBSE > Class 09 > Science

4 answers

Priya Priya 4 years ago

Diffusion of solvent molecules through semi-premerable from the region low concentration to region of high concentration form osmosis

Bhumikarani Pradhan 4 years ago

The movement of water molecules through a selective permeable membrane along the conversation gradient is called osmosis. Osmosis is also defined as the water molecules from a region of its higher concentration through a semipermeable membrane.

Vedant Motewar 4 years ago

Osmosis is the special type of diffusion in which it only take place in liquids.The concentration of solvent from region of higher concentration to the region of lower concentration. Like exchqnge of water in plants

Rashi Aastha 4 years ago

a process by which molecules of a solvent tend to pass through a semipermeable membrane from a less concentrated solution into a more concentrated one.

ANSWER

What is elemant

Posted by Gokul Settu 4 years ago

CBSE > Class 09 > Science

1 answers

Rashi Aastha 4 years ago

each of more than one hundred substances that cannot be chemically interconverted or broken down into simpler substances and are primary constituents of matter. Each element is distinguished by its atomic number, i.e. the number of protons in the nuclei of its atoms.

ANSWER

What is the valency of iron

Posted by Pranav G Nath 4 years ago

CBSE > Class 09 > Science

5 answers

Vaibhav Attri 4 years ago

Valency of iron is 2,3

Anushka Agarwal 4 years ago

Iron has 2 valencies: Ferrous has a valency of 2. Ferric has a valency of 3.

Bhumika Rani Pradhan 4 years ago

The valency of iron is 2...

Lavishka Choudhary 4 years ago

Valency of Iron (Fe) 2, 3 , atomic no. is 26

Shivam Kumar 4 years ago

Atomic number is 26 Valency is 2,3

ANSWER

What ia sustainable development

Posted by Saumya Kashyap 4 years ago

CBSE > Class 09 > Science

1 answers

Lavishka Choudhary 4 years ago

Sustainability is development that satisfies the needs of the present without compromising the capacity of future generations, guaranteeing the balance between economic growth, care for the environment and social well-being.

ANSWER

Explaine the difference between 2N and N^2

Posted by Utkarsh Dhiman 4 years ago

CBSE > Class 09 > Science

1 answers

Bhumika Rani Pradhan 4 years ago

2N means to molecules of Nitrogen atom. N^2 two atoms of nitrogen in its one molecules. N^2 shows that two atoms are bonded with covalent bond, and it become nitrogen gas whereas 2N doesn't show any bond, it just show two numbers of nitrogen only.

ANSWER

What do you mean by nucleus

Posted by Nikhil Rajput 4 years ago

CBSE > Class 09 > Science

3 answers

Beyon P Binoy 4 years ago

Nucleus is the brain of the cell.

Bhumika Rani Pradhan 4 years ago

Nucleus:- It is popularly called as the brain of cell. It is composed of double layer covering called head nuclear membrane. It has numerous pores called nuclear pores. They transfer the materials from inside the nucleus to cytoplasm. The nucleus contains chromosomes. When they are visible as rod-shaped structure only when the cell is about to divide. It encloses a liquid ground substance called nucleoplasm. It contains nucleolus and chromatin materials. Thank you...

Divya Gupta 4 years ago

The cell nucleus is a membrane bound structure that contains a cell's hereditary information and controls it's growth and reproduction.It is the command center of a eukaryotic cell and usually the most notable cell organelle in both size and function

ANSWER

Why do you fall in the forward direction when a moving bus brakes to a stop and fall backwards when it accelerates from rest ?

Posted by Muskan Singh 4 years ago

CBSE > Class 09 > Science

3 answers

Bhumika Rani Pradhan 4 years ago

We fall backward when a bus accelerates from rest. This happens because the person and the bus both are in rest while the person is not moving as bus starts moving. The leg of the person starts along with the bus, but rest position of the body has tendency to remain in rest. Because of this, person falls backward if he or she is not alert.

Kamya Gandhi 4 years ago

We fall in the forward direction when a moving bus brakes to a stop cuz of interia of motion and fall backwards when it accelerates from rest cuz of interia of rest

Beyon P Binoy 4 years ago

Due to the Inertia of Rest and Inertia of Motion.

ANSWER

Moon and earth both exert force on each other then why moon don't fall on the surface of earth??

Posted by Zoya . 4 years ago

CBSE > Class 09 > Science

1 answers

Nikhil Kumar 4 years ago

Because sun and other planets also exert force in moon that's why don't fall on earth

ANSWER

The frequency of a visible light of wavelength 600 nm is (speed of light = 3×10⁸ m/s), (1nm = 1‐⁹ m)

Posted by Jashith Sharma 4 years ago

CBSE > Class 09 > Science

2 answers

Jashith Sharma 4 years ago

Options :- a) 50Hz b) 5 × 1014 Hz c) 0.5 × 1016 Hz d) 500 Hz Please I need the answer

Ananya K 4 years ago

The wavelength of the light is, lamda = 600 nm =600 × 10-⁹ m

ANSWER

Why we are advised to take nutritional food when we are sick

Posted by Kavin Kathiresan A.P.A 4 years ago

CBSE > Class 09 > Science

4 answers

Kamya Gandhi 4 years ago

All the normal functions of the body get disturbed in case illness. So, a nourishing food is required, which is easily digestible and contains all the nutrients. This is the main reason that bland and nourishing food is advised to take during sickness.Because it helps in our nutritional growth

Yogita Ingle 4 years ago

All the normal functions of the body get disturbed in case illness. So, a nourishing food is required, which is easily digestible and contains all the nutrients. This is the main reason that bland and nourishing food is advised to take during sickness.

Khushi Chauhan 4 years ago

Hdis

Roshan Pandey 4 years ago

Because it helps in our nutritional growth

ANSWER

Anand leaves his house at 8.30 A.M for his school. The school is 2 km away and classes start at 9.00 A.M. If he walks at a speed of 3 km/h for the first kilometre, at what speed should he walk the second kilometre to reach just in time?

Posted by Mishika Pandey 4 years ago

CBSE > Class 09 > Science

1 answers

Ananya K 4 years ago

A--------------B--------------C Let A is Anand house B is 1km distance apart from his house C is school We know time = distance --------------- Speed tAB = 1 --- 3 tAB is the time taken from A to B tBC = 1 - 1 =1 ---. ---. --- hours 2. 3. 6 So, speed = distance. 1 --------------- = -------- time. (1/6) = 6 km/h

ANSWER

Why common salt is said to be a substance and salty water a mixture?

Posted by Vansh Arora 4 years ago

CBSE > Class 09 > Science

1 answers

Yogita Ingle 4 years ago

Common salt is a pure substance(compound) because it is made up of 2 types of elements, i.e., Sodium and Chlorine. These 2 substances cant be separated by physical processes. While, salty water is a mixture of water and salt and can be separated by physical processes like evaporation.

ANSWER

Give an example of atoms,molecules and Ion

Posted by Asika A 4 years ago

CBSE > Class 09 > Science

1 answers

Bhumika Rani Pradhan 4 years ago

1.ATOMS :- Hydrogen, Carbon, Oxygen, Phosphorus, Sulphur, Iron, Copper, Lead, Silver, etc. 2.MOLECULES :- Water, Ammonia, Carbon dioxide, Hydrogen Sulphide, Sulphuric Acid, Glucose, Backing Powder, Common Salt, Limestone or Calcium Carbonate, etc. 3. IONS :- Na+, K+, Ca2+, etc.

ANSWER

A solution contains 40g of common salt in 320g of water. Calculate the concentration in terms of the mass by mass percentage of the solution

Posted by Akshaya Shree 4 years ago

CBSE > Class 09 > Science

2 answers

Harsh Saini 4 years ago

Mass of solute=40g ". ". Solvent= 320g Mass of solution= mass of solute+ mass of solvent 40+320 = 360 Mass by mass formula= Mass of solute × 100 = Mass of solvent 40 x 100 = 4 × 100 now do it by your self 360. 36

Yogita Ingle 4 years ago

Mass of solute = 40g

Mass of solvent = 320g

Mass of solution = Mass of solute + Mass of solvent
= 40g + 320g
= 360gMass percentage of solution = (Mass of solute/Mass of solution)x100
=   40 / 360 x 100

= 11.1%

ANSWER

Describe plasma membrane and its functions ?

Posted by K.Kaviya Ix A 9032 4 years ago

CBSE > Class 09 > Science

1 answers

Vidhi Srivastav 4 years ago

It is a jelly like structure surrounded by the cell wall making selective things passing through it ♦ It's Function are :- # It provides rigidity to cell # It do not allow every thing passing through it # It helps in changing of substance in the cell only ♦ Mark me as the brainliest answer

ANSWER

Explain functions of the cells ?

Posted by K.Kaviya Ix A 9032 4 years ago

CBSE > Class 09 > Science

1 answers

Vidhi Srivastav 4 years ago

The basic processes of life include organization, metabolism, responsiveness, movements, and reproduction. In humans, who represent the most complex form of life, there are additional requirements such as growth, differentiation, respiration, digestion, and excretion.

ANSWER

State the law of conservation of mass. Is this law applicable to the chemical reaction? Elaborate your answer with the help of an example?

Posted by Sneha Singh 4 years ago

CBSE > Class 09 > Science

2 answers

Yogita Ingle 4 years ago

The law of conservation of mass states that mass in an isolated system is neither created nor destroyed by chemical reactions or physical transformations.

According to the law of conservation of mass, the mass of the products in a chemical reaction must equal the mass of the reactants.

The law of conservation of mass is useful for a number of calculations and can be used to solve for unknown masses, such the amount of gas consumed or produced during a reaction.

It is applicable in a chemical when the the mass of the products in a chemical reaction is equal to the mass of the reactants.

But it is not applicable in a nuclear fusion as some of the mass is generated as energy.

Sneha Singh 4 years ago

Ch 3 Atoms & Molecules

ANSWER

Distinguish between: a) Physical change and Chemical change any 3 point

Posted by Vedant Bhadra 4 years ago

CBSE > Class 09 > Science

2 answers

Yogita Ingle 4 years ago

Physical Change	Chemical Change
When a substance undergoes a physical change, its composition remains the same despite its molecules being rearranged.	When a substance undergoes a chemical change, its molecular composition is changed entirely. Thus, chemical changes involve the formation of new substances.
Physical change is a temporary change.	A chemical change is a permanent change.
A Physical change affects only physical properties i.e. shape, size, etc.	Chemical change both physical and chemical properties of the substance including its composition
A physical change involves very little to no absorption of energy.	During a chemical reaction, absorption and evolution of energy take place.
Some examples of physical change are freezing of water, melting of wax, boiling of water, etc.	A few examples of chemical change are digestion of food, burning of coal, rusting, etc.
Generally, physical changes do not involve the production of energy.	Chemical changes usually involve the production of energy (which can be in the form of heat, light, sound, etc.)

Vedant Bhadra 4 years ago

Pls tell me

ANSWER

What is paramchyma tissue

Posted by Daksh Choudhary 4 years ago

CBSE > Class 09 > Science

1 answers

Yogita Ingle 4 years ago

Consist of live unspecialized cells having thin cell wall.
They are loosely packed and have large intercellular space (space between the cells).
Provides support to the plant and present in all parts like roots, stems, leaves, fruits and seeds.
Storage of food (eg. Fruits) and water (in stems eg. cactus) is the main function.
Sometimes, these tissues also contain chlorophyll and perform photosynthesis, and known as chlorenchyma.
In case of aquatic plants, parenchyma is modified into aerenchyma.
Aerenchyma is the tissues having large air cavities which provides buoyancy to the plants and help them to float.

ANSWER

Iron pins from sands is which sepration

Posted by Shubham Sharma 4 years ago

CBSE > Class 09 > Science

5 answers

Gunu Ahmed 4 years ago

Separation through magnet

Beyon P Binoy 4 years ago

Seperation through magnet

Aastha Tiwari ? 4 years ago

Using magnet.. Magnet will attract all the iron pins and thus it will be separated

Priyanshu Raj 4 years ago

Using magnets

Riya Mangang 4 years ago

By using magnets

ANSWER

Chemical name of sulphuric acid

Posted by Riya Mangang 4 years ago

CBSE > Class 09 > Science

2 answers

Beyon P Binoy 4 years ago

H2SO4 - sulphuric acid

Divya Gupta 4 years ago

Chemical name for sulphuric acid is H2SO4

ANSWER

Chemical formula of lead(ii) chloride

Posted by Riya Mangang 4 years ago

CBSE > Class 09 > Science

2 answers

N K 4 years ago

Chemical formula of chloride is Cl

Om Shivhare 4 years ago

Mam we have to write thory in 2.3 exercise

ANSWER

Name the most abundant element in the earth's crust

Posted by Tarun Sharma 4 years ago

CBSE > Class 09 > Science

5 answers

Aastha Tiwari ? 4 years ago

Oxygen

Rohit Gupta 4 years ago

Oxygen

Yogita Ingle 4 years ago

The most abundant element in the earth’s crust is oxygen (46. 1%). The chemical formula of oxygen also known as dioxygen is O₂. This formula is given so because oxygen usually combines with another oxygen by forming a covalent bond.

Kamya Gandhi 4 years ago

Sorry for blah right ans. Is The mass-abundance of the nine most abundant elements in the Earth's crust is approximately: oxygen 46%, silicon 28%, aluminum 8.3%, iron 5.6%, calcium 4.2%, sodium 2.5%, magnesium 2.4%, potassium 2.0%, and titanium 0.61%.

Kamya Gandhi 4 years ago

Blah

ANSWER

Page 177 of 1371

myCBSEguide App

myCBSEguide

Trusted by 1 Crore+ Students

Test Generator

Test Generator

Create papers online. It's FREE.

CUET Mock Tests

CUET Mock Tests

75,000+ questions to practice only on myCBSEguide app

Google Play

Download myCBSEguide App