علوم 10: تكاثر البكتيريا والعناصر

Summary of Information

• Course: Cosmic Sciences
• Grade: Ninth
• Date: 26/12/2024
• Teacher: Muhammad Yusuf
• School: Al-Iman Schools

Classroom Rules

• Respect: Respect teachers, classmates, and the school.
• Responsibility: Be on time for class.
• Listening: Listen attentively to teachers and classmates.
• Quiet: Maintain silence and order during the lesson.
• Creativity: Follow the teacher's instructions quickly and accurately.
• Positivity: Be respectful of others.
• Participation: Participate politely with teachers and others.

Atomic Structure

• Crookes' Experiment: Crookes tested Dalton's atomic model, which described the atom as a solid, indivisible sphere.
• Cathode Ray Tube (CRT): CRTs used in televisions and computers demonstrate that cathode rays are particles, not light, and carry a negative charge, which are called electrons. These particles are present in all materials. Experiments with different metals for cathodes are used. A positive electrode in the tube is called an anode.
• Thomson's Model: Thomson's model envisioned an atom as a sphere of positive charge with negatively charged electrons embedded within it throughout.
• Rutherford's Experiment: Rutherford and his colleagues conducted experiments in 1908 to verify Thomson's model.
• Rutherford's Model: Most alpha particles passed through the gold foil without deflecting significantly, indicating that most of the atom is empty space. Some alpha particles were deflected at large angles, suggesting a concentrated, positively charged nucleus at the atom's center. The nucleus was supposed to have a higher positive charge to be able to repel the alpha particles. This model proved that Thomson’s model failed.
• Atomic Model (Modern): The modern model of the atom describes electrons orbiting a nucleus containing protons (positive charge) and neutrons (no charge).
• Isotopes: Atoms of the same element with different numbers of neutrons are called isotopes. The nucleus of carbon-12 is the most stable isotope because it has an equal number of protons and neutrons.
• Atomic Number: The number of protons in an atom. The atomic number is equal to the number of electrons.
• Mass Number: The sum of protons and neutrons in an atom's nucleus.
• Neutrons: The subatomic particle with no charge, same mass as the proton.
• Electron: A negatively charged subatomic particle, nearly massless.

Atomic Models

• Dalton's Model: A solid sphere model.
• Thomson's Model: Positive sphere with negative electrons embedded.
• Rutherford's Model: Positive nucleus with electrons orbiting around it.
• Bohr's Model: Electrons orbit the nucleus in specific energy levels.
• Modern/Cloud Model: Electrons exist in a cloud-like region around the nucleus.

Radioactive Decay

• Radioactive Decay: The process of unstable atomic nuclei releasing particles and energy until they become stable. Transmutation is when one element is changed to another through radioactive decay. Alpha particles, beta particles, and gamma rays are types of radiation produced during radioactive decay.

Periodic Table

• Periodic Table of Elements: A table that organizes chemical elements based on their atomic number, electronic configuration, and recurring chemical properties.
• Periods: Horizontal rows in the periodic table.
• Groups/Families: Vertical columns in the periodic table.
• Metals: Elements located on the left side and middle of the periodic table.
• Non-metals: Elements located on the right side of the periodic table.
• Metalloids (Semi-metals): Elements with properties of both metals and non-metals. They are located between metals and nonmetals on the "zigzag" line of the periodic table.
• Transition Metals: Elements found in the "middle blocks" of the periodic table.
• Inner Transition Metals: Elements located at the bottom of the periodic table (lanthanides and actinides).
• Properties: The Periodic Table organizes elements based on their atomic number and repeating (periodic) properties.

Chemistry of Cells

• Cell Membrane: A thin, flexible barrier surrounding the cell.
• Cell Transport: The process of materials (including water, nutrients, or waste) moving in and out of the cell .
• Passive Transport: Moves materials across membranes without energy.
• Diffusion: Movement of materials from a high concentration area to a low concentration area.
• Osmosis: The movement of water from a high concentration to a low concentration across a semipermeable membrane.
• Facilitated Diffusion: The movement of materials across membranes using protein channels, without energy.
• Active Transport: Moves materials from a low concentration to high concentration.
• Endocytosis (Phagocytosis, Pinocytosis): The process of moving large materials into the cell.
• Exocytosis: The process of moving large materials out of the cell.
• Photosynthesis: The process in which plants use sunlight to make food.
• Cellular Respiration: The process by which cells break down food to release energy.
• Metabolism: All chemical reactions in a cell.
• Enzyme: A protein that speeds up chemical reactions in organisms.

Cell Division

• Cell Cycle: A series of events that take place in a cell leading to its duplication (replication).
• Mitosis: A type of cell division that produces two identical daughter cells from one parent cell.
• Meiosis: A type of cell division that produces four genetically different daughter cells from one parent cell, resulting in gamete (sperm or egg) formation.
• Cell Reproduction/Growth and Repair: Mitosis is important for growth, repair of damaged tissues, and asexual reproduction in some organisms.
• Asexual Reproduction: A type of reproduction that does not involve the fusion of gametes.
• Sexual Reproduction: A type of reproduction that involves the fusion of gametes.

Plate Tectonics and Earth Processes

• Plate Tectonics: The theory explaining the movement of Earth's lithospheric plates.
• Faults and Earthquakes: Zones where plates in the Earth's crust meet; sometimes rupture causing earthquakes.
• Earthquake Epicenter: The point on the Earth's surface directly above the focus.
• Earthquake Focus: The point in the Earth's interior where an earthquake originates.
• Seismic Waves: Waves that travel through the earth during an earthquake.
• P-waves (Primary waves): Fastest seismic waves, travel through solids, liquids, and gases.
• S-waves (Secondary waves): Slower seismic waves, travel only through solids.
• Surface waves: Slowest, most destructive of seismic waves, travel only along the surface of the earth.
• Seismograph: A device used to record seismic waves.
• Richter Scale: A scale used to measure the magnitude of an earthquake.
• Mercalli Scale: A scale used to measure the intensity of an earthquake based on the amount of damage.
• Tsunamis: Large waves in a body of water (an ocean) caused by an earthquake or volcanic eruption. The waves are created by the displacement of a large volume of water.
• Volcanoes: Features that allow magma to rise to the surface from Earth's interior. A volcano is composed of:
  • Magma: Molten rock under the Earth's surface.
  • Lava: Magma that flows onto the Earth's surface.
  • Pyroclastic Material: Solid bits of rock or lava ejected into the air during a volcanic eruption.
  • Gases: Gases are released during a volcanic eruption.
• Types of Volcanoes: Types of volcanoes include shield volcanoes, composite volcanoes, and cinder cones.

Errors in Cell Division and Reproduction

• Chromosomal Abnormalities: Errors in cell division or reproduction can cause chromosomal abnormalities, resulting in an incorrect number of chromosomes or altered genetic material (mutations).
• Examples: Down syndrome, which is caused from an extra chromosome.