Senior High School General Science Review

Vocabulary flashcards covering acids and bases, human excretory systems, gaseous exchange, basic electricity, buoyancy, electronics, pathogenic diseases, and indigenous beverage production from the SHS Year 2 General Science curriculum.

Acids

Substances that release hydrogen ions ($H^+$) when dissolved in water, usually taste sour, and turn blue litmus paper red.

Bases

Substances that accept hydrogen ions or release hydroxide ions ($OH^-$) in water, frequently feeling slippery and tasting bitter.

Neutralisation

The chemical reaction between an acid and a base to form salt and water only, represented by the equation: $Acid + Base \rightarrow Salt + Water$.

pH Scale

A scale ranging from $0$ to $14$ used to identify the concentration of acids and bases, where below $7$ is acidic, $7$ is neutral, and above $7$ is basic.

Molarity (M)

A measure of solution concentration expressed in moles per litre ($mol/dm^3$).

Organic Acid

Acids derived from living things (plants and animals) that contain carbon in their chemical structure, such as Citric acid or Acetic acid.

Inorganic Acid

Also known as mineral acids, these are made from minerals and do not naturally come from living things, such as Hydrochloric acid ($HCl$) or Sulphuric acid ($H_2SO_4$).

Salt

An ionic compound formed when the hydrogen ($H^+$) of an acid is replaced by a positively charged cation from a base.

Molar Mass

The mass of one mole of a substance, expressed in grams per mole ($g/mol$), calculated by summing the atomic masses of all atoms in a chemical formula.

Homeostasis

The process of maintaining a stable internal environment within the human body to ensure optimal functioning.

Excretion

The biological process by which an organism eliminates metabolic waste, harmful substances, and regulates water, pH, and ion levels.

Epidermis

The thin, outermost layer of the skin that provides a waterproof barrier and protects the body from pathogens and sunlight.

Dermis

The thick middle layer of the skin containing sweat glands, hair follicles, nerves, and blood vessels.

Hypodermis

The bottom layer of the skin made mostly of fat, acting as insulation and padding for muscles and bones.

Bilirubin

A yellowish pigment produced during the breakdown of red blood cells, which is processed by the liver and excreted in bile.

Nephron

The functional unit of the kidney, with over a million per kidney, responsible for filtering blood and forming urine.

Glomerulus

A bundle of tiny blood vessels in a cup-like structure called Bowman’s capsule where the filtration of blood begins in the nephron.

Breathing

The physical process of taking oxygen into the lungs (inhalation) and releasing carbon dioxide into the atmosphere (exhalation).

Alveoli

Tiny air sacs at the end of bronchioles where gaseous exchange occurs between the lungs and blood capillaries via diffusion.

Aerobic Respiration

The biochemical process in cells that uses oxygen to convert glucose into energy ($ATP$), releasing carbon dioxide and water as by-products ($C_6H_{12}O_6 + 6O_2 \rightarrow 6CO_2 + 6H_2O + \text{energy}$).

COPD

Chronic Obstructive Pulmonary Disease, a progressive lung disorder characterized by breathing difficulties and airflow blockage.

Electric Current (I)

The rate at which electric charge ($Q$) flows through a conductor, measured in Amperes ($A$) using the formula $Q = I \times t$.

Voltage (V)

The electric potential difference or 'push' that makes charges flow through a circuit, measured in Volts ($V$).

Resistance (R)

The measure of opposition to the flow of current in an electrical circuit, measured in Ohms ($\Omega$).

Ohm's Law

States that at constant temperature, the current is directly proportional to the applied voltage ($V = I \times R$).

Kilowatt-hour (kWh)

The unit of electrical energy consumption used for domestic billing, equivalent to $3,600,000$ Joules.

Transformer

An electrical device that uses electromagnetic induction to change the voltage level of alternating current ($AC$).

Step-up Transformer

A transformer that increases voltage while decreasing current, having more turns in the secondary winding than the primary.

Step-down Transformer

A transformer that decreases voltage while increasing current, having fewer turns in the secondary winding than the primary.

Upthrust

The upward buoyant force exerted by a fluid on an object submerged in it, acting against the object's weight.

Archimedes' Principle

States that the buoyant force acting on an object submerged in a fluid is equal to the weight of the fluid it displaces.

Law of Flotation

States that a floating object displaces a weight of fluid equal to its own weight.

Semiconductors

Materials like Silicon that behave as both conductors and insulators depending on conditions like heat, light, or doping.

Doping

The process of adding small amounts of impurities to a pure semiconductor to control its electrical conductivity.

n-type Doping

Adding impurities with more electrons (e.g., Phosphorus in Silicon) to create extra free negative charge carriers.

p-type Doping

Adding impurities with fewer electrons (e.g., Boron in Silicon) to create 'holes' that act as positive charge carriers.

p-n Junction

The area where p-type and n-type materials meet, forming a depletion region that allows current to flow in one direction only.

Pathogen

A microorganism such as a bacterium, virus, fungus, or parasite that invades the body and causes disease.

Incubation Period

The time between exposure to a pathogen and the appearance of the first symptoms.

Sobolo

A traditional Ghanaian beverage made from dried hibiscus petals infused with ginger and other spices.

Asana

A popular non-alcoholic beverage in Ghana made from fermented corn and caramelised sugar.

Fermentation

A biological process where microorganisms like yeast convert sugars into alcohol and carbon dioxide.

Distillation

A process of separating components in a liquid mixture based on different boiling points, used to produce high-alcohol spirits like Akpeteshie.