https://youtu.be/tiqiN3y1ze4?si=l4EcsHAfhhkzwple
REFRACTION - CRITICAL ANGLE
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https://youtu.be/NAaHPRsveJk?si=y_c9gVy2px_GXBUz
TOTAL INTERNAL REFLECTION
https://youtu.be/ybvjcjndn_4?si=Hmcgn7ndFHNcHTWa
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COLOUR THEORY
https://youtu.be/S9T0V5Mh01g?si=M68YV-1A4ccOxeI9
https://youtu.be/xvfwuImlkrA?si=lcPbiSx_-8aOLdrV
Scalar Quantities
Scalar quantities have only magnitude (size or amount) and no direction.
Here are 10 examples:
1. *Temperature* - Example: 25 degrees Celsius.
2. *Speed* - Example: 60 kilometers per hour (km/h).
3. *Mass* - Example: 50 kilograms (kg).
4. *Time* - Example: 30 seconds.
5. *Volume* - Example: 2 liters (L).
6. *Distance* - Example: 10 meters (m).
7. *Energy* - Example: 100 Joules (J).
8. *Density* - Example: 1.2 grams per cubic centimeter (g/cm³).
9. *Electric charge* - Example: 2 Coulombs (C).
10. *Area* - Example: 20 square meters (m²).
Vector Quantities
Vector quantities have both magnitude and direction. Here are 10 examples:
1. *Velocity* - Example: 50 km/h east.
2. *Force* - Example: 10 Newtons (N) upward.
3. *Displacement* - Example: 5 meters north.
4. *Acceleration* - Example: 2 meters per second squared (m/s²) to the right.
5. *Momentum* - Example: 20 kg·m/s south.
6. *Electric field* - Example: 3 Newtons per Coulomb (N/C) downward.
7. *Magnetic field* - Example: 0.5 Tesla (T) towards the west.
8. *Weight* - Example: 500 Newtons downward (due to gravity).
9. *Torque* - Example: 15 Newton meters (N·m) clockwise.
10. *Lift* - Example: 800 Newtons upward (as in an airplane's lift).
*Scalars*:
- Scalars are like counting objects or measuring something without worrying about which way it's going. For example, if you measure the temperature of the room, you only care about how hot or cold it is, not which direction the heat is coming from.
*Vectors*:
- Vectors are like giving directions with measurements. For example, if you tell someone to walk 10 meters north, you are giving them both a distance and a direction to follow. Both parts (the distance and the direction) are important to understand what you mean.
These examples should help you understand the difference between scalar and vector quantities. Scalars are simpler because they only have a size, while vectors are more detailed because they tell you both size and direction.
Homologous series are characteristic of
organic compounds because these compounds are based on carbon chains. In a homologous
series, each member differs from the next by a CH₂ unit. This regularity in
structure leads to a gradual variation in physical properties and similar
chemical properties among the members. Inorganic compounds, on the other hand,
do not form such series because their structures are more varied and less
amenable to the regular incremental changes seen in organic compounds.
Methane (CH₄), ethane (C₂H₆), and propane
(C₃H₈) are all alkanes, which are saturated hydrocarbons. They have similar
chemical properties because they all undergo similar types of reactions, such
as combustion and substitution, due to the presence of only single bonds
between carbon atoms. However, they differ in physical properties such as
boiling and melting points. These differences arise because as the molecular
size increases, the strength of van der Waals forces between the molecules
increases, leading to higher boiling and melting points for larger molecules.
Hydrocarbons in the same homologous series
share a common general formula, which describes the ratio of carbon to hydrogen
atoms in the molecules. For example:
- Alkanes have the general formula (CnH{2n+2} -- Alkanes (paraffins)
- Alkenes have the general formula (CnH{2n} --- Alkenes (olefins)
- Alkynes have the general formula (CnH{2n-2}
This general formula is a result of the consistent structural pattern within
the series, where each successive compound differs by a CH₂ group.
