an iron almirah is a solid because it has definite shape. You cannot flow it means it is solid.
Tuesday, April 28, 2020
water at room temperature is a liquid give two reason to justify
Water is liquid at normal temperature because it has no definite shape. It acquires the shape of the same container in which it is kept. Secondly it can flow easily. It means it is liquid not solid
we can get the smell of perfume sitting several metre away give reason
Particles of scent mix with the particle of air automatically and spread everywhere. Due to this scattering of particles a man sitting at some distance can a smell the scent
Naphthalene balls disappear with time without leaving any solid give reason
Naphthalene balls disappear without leaving any Residue because they are sublimated. In other words they are converted into gaseous state directly
why is ice at 273 K more effective in cooling than water at the same temperature
The energy of ice particles at 273 k A remains lower to the particles of water. As a result ice can absorb more energy from atmosphere this is the reason why being on equal temperature ice can cool more than water
Monday, April 27, 2020
what produce more Severe Burns boiling water or stream
At 373 K the energy of particles of vapour remains greater than the energy of particle of water at equal temperature. This happens due to the fact that particles of vapour absorb excess energy in form of latent heat of vaporization Hence when vapour comes in contact of a screen it is releasing energy more than the water boiling at the same temperature as a result steam produce more Severe burns than boiling water
why should we wear cotton clothes in summer
cotton clothes are good absorbers of water it helps in absorption of sweat and leaves it exposure for simple vaporization the sweat turns into vapour very fast the latent heat of vaporization is taken from the body and we feel good
Sunday, April 26, 2020
what type of clothes should we wear in summer
In summer we should wear white or light colour cloth white aur light coloured clothes are good reflector of light due to this we feel cool
why are we able to sip hot tea or milk faster from a saucer rather than a cup
The area of surface of Milk or tea in a cup is less. It cause slow evaporation due to which it becomes old slowly so it takes time in sipping when the tea is kept in a plate the area of the surface of milk or tea increases it it leads to fast evaporation. Thus, it takes list time in cooling show the milk or tea can be sipped quickly
why does our Palm feel cold when we put some Acetone or petrol or perfume on it
Acetone/ petrol or scent are volatile substance when these are put on plan their vaporization becomes faster due to the plum for this the substance take energy from the plan due to which it become cold
how does the water kept in an pitcher ( Earthen pot, Matka) become cool during summer
During summer there is less water vapour in atmosphere teachers have a small pores though which water keeps up coming out slowly. This happens around the pitches it leads to cooling a water of the pitcher.
why does a desert cooler cool better on a hot dry day
Hot dry days have less water vapour in atmosphere they encourage to increase the rate of evaporation. Cooler runs its water it takes energy from atmosphere for its vaporization and evaporated fast. Thus cooler cools better on a hot dry day
why do liquids have fixed volume
A liquid has fixed volume because the space among its molecule at a given temperature is fixed
why do solid have fixed shape
Particles of solid have greater force of attraction the remains close to each other in they have fixed shapes.
why do gases not have a fixed shape nor a fixed value
Gases do not have fixed shape. This is because the position of their molecules is not fixed gases do not have fixed volume because the area of a space between their molecules is not fixed
liquid generally have lower density as compared to solids but you must have observed that ice floats on water find out why
FB status of AI floats on water because its volume is Greater if can replace water having more weight this is the reason why a fishes of ice floats on water the volume of ice is greater than the water of which it is made
when we can easily move our hand in air but to do the same through a solid block of wood we need to be a Karate expert give reason
we can move hand in we can move hand in air is leave because its molecule can easily the displays it is so because they have very less force between them. Particles of would have very less space left among them in the force of attraction is Greater there so for moving our hand though a solid block of wood far greater force is needed which is possible only for an expert of karate
a wooden table should be called a solid give reason
Particles of wood are connected with great forces it is called as solid table is made of wood is it is called solid
a gas fills completely The vessel in which it is kept give reason
Particles of a gas remain for a part other they have a property of flour due to this reason a gas spared in the entire container
what are the characteristics of the particles of matter
Characteristics of particle of matter -
- Particles of matter contain flank spaces.
- Particle of matter remain in continuous motion.
- Particle of matter attract each other.
A diver is able to cut through water in a swimming pool. which property of matter does this observation show
swimming pool has water which is swimming pool has water which is in liquid state. Proceeding through water indicate what the force applied between water particle is lesser. Due to this water molecule get separate easily
give reason for the following observation - the smell of hot sizzling food reaches you several metres away but to get the mail from cold food you have to go close
Particles of a substance remain motile continually. When temperature rise the motion of particles become faster does mail from food reaches to us though diffusion. The temperature of hot food we mean by the diffusion rate of hot food remains as compared to cold food so it's made reach to us from several metres away
Saturday, April 18, 2020
where does similarity in isotopes of an element exists
Numbers of electrons and protons and remains same in isotope of a substance
Friday, April 17, 2020
atomic number of an element is 16 what will be its valency
- Electron configuration = 2, 8, 6
- Valency = 8 - 6 = 2
what can be the maximum number of electrons in a sale as per Bohr's Theory
2n², Where n is number of shell
which is equal and which is unequal in isotopes
Atomic number remains equal where an atomic mass is unequal
place the wavelength of radio waves x-ray UV rays visible rays and infrared rays in successive order
X-ray UV rays visible rays infrared and radio waves
what is the non relative mass and change on an electron
- Non relative mass of electron mass of electron = 9.109 × 10^–31 kg non relative change of non relative change of electron = 1.602 × 10^–19 C