Using exothermic reactions

• An exothermic reaction is a chemical or physical process that releases energy, most commonly as heat, into its surroundings.

• Enthalpy change (\(\Delta H\)) is the heat absorbed or released by a system during a process at constant pressure.

  
  

• A neutralization reaction is a chemical reaction between an acid and a base that produces a salt and water.

• Mixing epoxy resin and hardener is a chemical reaction called polymerization, where a liquid two-part epoxy system cures into a solid, rigid material through a process called cross-linking

• A strong acid completely ionizes in water to produce a large amount of hydrogen ions (\(H^{+}\)), while a weak base only partially ionizes in water, creating fewer hydroxide ions (\(OH^{-}\)).

1. Thallophytes (Algae)

• Simplest plants — no true roots, stems, or leaves.

• They grow mostly in water (fresh or salty).

• They make their own food using sunlight (photosynthesis).

• Some are green, others can be red or brown.

• Examples: Spirogyra, Seaweed, Ulva, Volvox

Importance of Price Elasticity of Demand (PED) for Decision Makers

Knowing about PED helps businesses, consumers, and the government make better decisions about prices and demand.

For Producers (Businesses)

• If demand is price inelastic (people keep buying even if price rises), the firm can increase prices to earn more revenue. Example: Medicine or petrol.

• If demand is price elastic (people stop buying when price rises), the firm should avoid raising prices because sales will fall a lot. Example: Soft drinks or snacks.

1. Predicting the Effect of Exchange Rates

1. Immune system will protect you.

2. but sometimes, your immune system gets weak.

Determinants of Price Elasticity of Demand (PED)

These are the factors that decide how strongly people react when the price changes.

1. Substitutes (Other Choices)

• If people can easily find another product, they will switch when the price goes up → Elastic Example: Pepsi and Coca-Cola.

• If there are no other options, people still buy it → Inelastic Example: Medicine or toothpaste.

2. Income (Money Spent)

A species is a group of living things that share many things in common. They look alike, live in similar ways, and can have babies with each other. The babies they have can also grow up and have babies of their own.

Each species has its own special features. For example, all humans belong to one species because all people can have children together. All dogs belong to another species because all dogs can have puppies together.

Different species cannot have babies together. For example, a cat and a dog are too different. Their bodies, size, and the way their insides work are not the same, so they cannot have babies together.

Every species has its own kind of food, place to live, and way of surviving. Fish live in water and breathe through gills. Birds live on land or in trees and breathe air through lungs. Lions hunt for…

i did khan academy and did you know \large 554984 + 23023 = 578007

The parts of a flower:

Cell Structure

• When a very thin slice of a plant stem is looked at under a microscope, it looks like it’s made up of many small box-like parts — these are cells.

• The slice in the picture is magnified 60 times. So if a cell looks 2 mm long in the image, in real life it’s only 0.03 mm long.

• Such thin slices are called sections.

Types of Sections

1. Longitudinal Section – Cut along the length of the stem (you see the inside part stretched out).