Properties of the states of matter and kinetic theory
What is the state of nitrogen at room temperature?
Gas
After a change of state, is the substance still the same? Why?
Yes. It only change the disposition of the particles. Chocolate Milk is still Chocolate Milk if frozen.
List the 3 states of aggregation water is found in naturally in the world,
Solid= Ice, Liquid= Water, and Gas= Clouds/ Steam
What are the variables that are related in a gas?
Pressure, temperature and volume
Define temperature in scientific terms. Do not just say "Hot and cold".
Temperature is a measure of the internal energy of a substance. Technically, it refers to the motion of the particles within the substance.
Can you compress the air? Why or why not?
Yes, because gas particles are further apart. There is space for them to be squeezed closer, reducing it's total volume.
When we change from solid to liquid it is called...
Melting
If the melting point of bromine is -7.2ºC and the boiling point 59ºC, In which state is at -5ºC?
Liquid
What happen with a ballon full of air if we place it on a dish with hot water?
Its volume will increase.
What are the most common units used to measure Temperature in science? How do we change from one to another?
Celsius (°C) and Kelvin (K).
T(K)=T(ºC)+273
Solids are made up of small particles and these particles don't move. True or false? Explain.
False, particles of matter are in continuous movement, essentially vibrating.
When we change from gas to liquid it is called....
Condensation
What is atmospheric pressure?
It´s the weight that the atmosphere exerts per unit of area.
What happens with a balloon if we put it in a vacuum chamber and then we remove the air from the chamber at constant T?
The volume of the balloon will increase.
What happens with the temperature when a substance starts to change it's state?
The temperature remains constant.
What is the Kinetic Particle Theory? What are its statements?
It is a theory that explains the behavior of matter (solid, liquid and gas) stating that matter is made up of particles invisible to the naked eye with forces of attraction among them.
These particles are in continuous movement, and this movement increases with temperature.
What are the two types of Vaporisation and their differences?
Evaporation: Happens at any Temperature on the surface of the liquid.
Boiling: Happens at a fixed Temperature for each substance and in the entire mass of the liquid.
On Venus water would boil at a Temperature higher than 100ºC. What can you conclude about the atmospheric pressure of Venus?
That it is higher than it is on Earth.
At constant pressure, the volume of a gas is directly proportional to its temperature in ºC. True or false? Explain.
False, the volume is directly proportional with its Temperature in Kelvin, not Celsius.
What are the three most common units used to measure pressure? What are their symbols?
Pascals (Pa) and Atmospheres (atm) and Millimeters of Mercury (mmHg)
Explain, from a microscopic perspective, why solids are denser than liquids and much denser than gases
Because in solids, particles are very close so the relationship between mass and volume(density) will be higher than in liquids and gases. The closer the particles, the more dense.
Why does the bathroom mirror steam up when you have a shower?
Because its surface is cooler so when the water vapour touches it, the vapour changes to liquid due to condensation.
Describe the experiment carried out by Torricelli to measure atmospheric pressure for the first time.
He used a 1 m tube full of mercury and introduced it on an open dish full of mercury. Then the level of mercury dropped to 0.76m from the surface of mercury.
Explain why a pressure cooker could be dangerous and the gas law that explains the scientific reason behind this
Because it can explode if the pressure gets too high. It is related with Gay-Lussac's law.
When we stick a suction cup to a window, we have to press down hard to make it stick. What keeps it stuck to the glass?
Atmospheric pressure. The pressure difference between the atmosphere on the outside of the cup and the low-pressure cavity on the inside of the cup keeps the cup adhered to the surface.