While alighting from the moving bus, the feet of the person will suddenly come to rest while rest of the body is in the state of motion due to inertia of motion and hence the person may fall down and may get injured.

A nuclear pore is a part of a large complex of proteins, known as a nuclear pore complex that spans the nuclear envelope, which is the double membrane surrounding the eukaryotic cell nucleus. There are approximately 1,000 nuclear pore complexes (NPCs) in the nuclear envelope of a vertebrate cell, but it varies depending on cell type and the stage in the life cycle. The human nuclear pore complex (hNPC) is a 110 megadalton (MDa) structure. The proteins that make up the nuclear pore complex are known as nucleoporins; each NPC contains at least 456 individual protein molecules and is composed of 34 distinct nucleoporin proteins. About half of the nucleoporins typically contain solenoid protein domains—either an alpha solenoid or a beta-propeller fold, or in some cases both as separate structural domains. The other half show structural characteristics typical of "natively unfolded" or intrinsically disordered proteins, i.e. they are highly flexible proteins that lack ordered tertiary structure. These disordered proteins are the FG nucleoporins, so called because their amino-acid sequence contains many phenylalanine—glycine repeats.

• The nuclear envelope contains many pores known as nuclear pores and encloses the liquid ground substance, the nucleoplasm.
• The nucleopores allow transfer of materials between the nucleoplasm and the cytoplasm. Within nucleoplasm are embedded two types of nuclear structures- nucleolus and chromatin material. 

The sunlight that reaches the earth’s atmosphere is scattered in all directions by the gases and dust particles present in the atmosphere. The blue colour is scattered more and hence the sky appears blue. The reason for more scattering of blue colour is that the wavelength of the blue light is shorter than the other light. So blue light is scattered in all directions by the tiny molecules of air in Earth’s atmosphere. This the reason for the blue appearance of the sky.

Atoms are made up of three subatomic particles, protons, neutrons and electrons.

• It is located in the stems and roots on the lateral side.

• It increases the thickness of the plant.

• Vascular cambium and cork cambium are the two lateral meristems.

• These divide preclinically or radially and give rise to secondary permanent tissues.

• Evaporation

• During summer, water kept in an earthen pot becomes cool because of the phenomenon of evaporation. Earthen pot has a large number of tiny pores in its walls and some of the water molecules continuously keep seeping through these pores to outside the pot. This water evaporates continuously and take the latent heat required for vaporization from the remaining water. In this way, the remaining water loses heat and gets cooled.

i) Molecular mass of H2= 2 x Atomic mass of H= 2 x 1
= 2 u

ii) Molecular mass of O2= 2 x Atomic mass of O
= 2 x 16
= 32 u

 iii) Molecular mass of NH3= Atomic mass of N + 3 x Atomic mass of H
= 14 + 3 x 1
= 17 u

Kinetic Energy

• It is the energy possessed by a body due to its motion. Kinetic energy of an object increases with its speed.
• Kinetic energy of body moving with a certain velocity = work done on it to make it acquire that velocity

Given:
Method I:
Initial speed=u=56km/h=56 x 5/18=15.55m/s
Final speed=v=58km/h=58x5/18=16.11m/s
Time=t=1sec
acceleration=a=?
as we know that acceleration is rate of change of velocity.
a=(v-u)/t
=(16.11-15.55)/1
=0.56 m/s²

Method 2:
Initial speed=u=56km/h
Final speed=v=58km/h
Time=t=1/60x60 h
acceleration=a=?
as we know that acceleration is rate of change of velocity.
a=(v-u)/t
=(58-56)/1/60*60
=2x3600
=7200 Km/h²
∴ Acceleration is 0.56 m/s² or 7200 Km/h²

Lysosomes are sphere-shaped sacs filled with hydrolytic enzymes that have the capability to break down many types of biomolecules. Lysosomes are known as suicide bags of the cell because they contain lytic enzymes capable of digesting cells and unwanted materials.

Or

They are called suicidal bags because :-

◼ They release enzyme outside the cell, which help in destroying materials around the cell and this process is known as exocytosis.

◼ In damaged cell, lysosomes burst to release enzymes for digestion.

As the motion is uniform, its acceleration will be 0m/s2.

Now,

Acceleration= (V - U)/t

0 = (V - 10 )/10

0×10 = V - 10

0 = V - 10

0 +10 = V

10 = V

So, the final velocity will be 10 m/s.

Height of second object from the ground after 2s then h₂ = 100m – 20m = 80m Now, difference in the height after 2s = h₁ – h₂ = 130 – 80= 50 m
The difference in hights of the objects will remain same with time as both the objects have been dropped from rest and are falling with same acceleration i.e., (acceleration due to gravity).

Study

he molar masses of all these substances will be equal to the respective molecular masses expressed in g / mol . Now :

(a) Molar mass of ethyne, C2H2 = Mass of C × 2 + Mass of H × 2

= 12 × 2 + 1 × 2

= 24 + 2

= 26 g / mol

(b) Molar mass of sulphur molecule, S8 = Mass of S × 8

= 32 × 8

= 256 g/ mol
 

We know that, the equations of uniformly accelerated motion are 

For an object moving with uniform velocity (velocity which is not changing with time), then acceleration
a = 0.
So, equations of motion will become (putting a = 0 in above equations)
(i) v =u                                        (ii) s =ut
(iii) v² =u² 

Brain cancer can arise from many different types of brain cells (primary brain cancer) or occur when cancer cells from other parts of the body spread (metastasize) to the brain. True brain cancers are those that arise in the brain itself.

Lysosomes are sphere-shaped sacs filled with hydrolytic enzymes that have the capability to break down many types of biomolecules. Lysosomes are known as suicide bags of the cell because they contain lytic enzymes capable of digesting cells and unwanted materials.

Nucleon is a collective name for two particles: the neutron and the proton. These are the two constituents of the atomic nucleus. Until the 1960s, the nucleons were thought to be elementary particles.

In 1911, Rutherford performed the gold foil experiment. He bombarded a stream of a-particles on a gold foil, a thin sheet which was 0.00006 cm thick in an evacuated chamber. An a-particle is a positively charged helium ion (He +).

Most of the a-particles passed straight through the foil without any deflection. This concluded that most of the space inside of an atom is empty.

(ii) A few particles were deflected through small angle and few through larger angles. This happened due to positive charge on particles and core (nucleus) of the atom. The heavy positively charged 'core' was named as nucleus.

(ii) The number of particles which bounced back was very small. This concluded that the volume of the nucleus is very small in comparison to the total volume of the atom. On the basis of gold foil experiment, Rutherford concluded that an atom consists of nucleus which has positive charge and it is surrounded with electrons which are moving around the nucleus. The number of electrons and protons are equal and the entire mass of the atom is concentrated at its nucleus. Drawbacks in the Rutherford's model          

(i) According to classical electro-magnetic theory, a moving charged particle, such as an electron under the influence of attractive force  loses energy continuously in the form of radiations. As a result of this, electron should lose energy and therefore, should move in even  smaller orbits ultimately falling into the nucleus. But the collapse does not occur. There is no explanation for this behavior.

(ii) Rutherford did not specify the number of orbits and the number of electrons in each orbit.

Plasma membrane is a thin membrane that surrounds every living cell, separating it from the external environment around it. The plasma membrane consists of water-soluble substances like nucleic acids, proteins, carbohydrates. Typically, the plasma membrane defines the boundary of a cell. Apart from protecting the constituents of the cell, substances are exchanged through the surface of the plasma membrane.

The plasma membrane is composed of lipids and proteins that contribute to the functioning of the membrane. Even though the plasma membrane is the only barrier between internal components of the cell and the extracellular environment in some species. In some organisms, have an extra-barrier, apart from plasma membrane called the cell wall. Functions of plasma membrane include protection, selective permeability, cell signaling, endocytosis and exocytosis.

Mixtures which have uniform composition throughout are called Homogeneous Mixture. For example – mixture of salt and water, mixture of sugar and water, air, lemonade, soda water, etc.

Mixtures which do not have uniform composition throughout are called Heterogeneous Mixture. For example – mixture of soil and sand, mixture of sulphur and iron fillings, mixture of oil and water etc. The boundaries of constituent particles of a homogeneous mixture can be identified easily; as a homogeneous mixture has two or more distinct phases.

An alloy is a material composed of two or more metals or a metal and non metal. It may be a solid solution of the elements of single phase or a mixture of two or more metallic phases. Solid alloys give a single solid phase microstructure. Alloys are used where their properties are superior to those of pure component elements. Examples are steel,solder,brass,amalgam etc.

ANSWER Na

Group one alkali metals are soft metals. Since, Na is an alkali metal so it is soft metal.  Non-Metals are generally Soft

They can be easily cut with knife.

For Ex: Sulphur ,Phosphorus.