কেমিস্ট্রি: পারমাণবিক গঠন ও রসায়নিক বন্ধন

Atomic Structure

• Atoms are the fundamental building blocks of matter.
• Atoms are composed of protons, neutrons, and electrons.
• Protons have a positive charge, neutrons are neutral, and electrons have a negative charge.
• Protons and neutrons reside in the atom's nucleus, while electrons orbit the nucleus in electron shells or energy levels.
• The number of protons in an atom determines its atomic number and defines the element.
• Isotopes are atoms of the same element with different numbers of neutrons. They have the same number of protons but different atomic masses.
• Atomic mass is the average mass of all the isotopes of an element, weighted by their relative abundance.
• Electron configuration describes the arrangement of electrons in the atom's orbitals.

Chemical Bonding

• Chemical bonds are forces that hold atoms together in molecules and compounds.
• Ionic bonds form when one atom donates electrons to another, creating ions with opposite charges that attract.
• Covalent bonds form when atoms share electrons.
• Metallic bonds occur between metal atoms, where electrons are delocalized and shared among all atoms in the structure.
• Intermolecular forces are attractions between molecules.
• Hydrogen bonds are a type of strong intermolecular force that occurs between molecules containing hydrogen bonded to a highly electronegative atom (e.g., oxygen or nitrogen).
• Van der Waals forces are weak intermolecular forces that arise from temporary fluctuations in electron distribution.

Periodic Table

• The periodic table is a tabular arrangement of elements that shows recurring trends or periodic properties.
• Elements are arranged by increasing atomic number.
• Elements in the same vertical column (group or family) have similar chemical properties.
• Elements in the same horizontal row (period) have increasing atomic numbers.
• The periodic table has periods (rows) and groups (columns) that help predict properties.
• Elements on the left side of the periodic table are typically metals, while elements on the right side are typically nonmetals.
• Metalloids exhibit properties of both metals and nonmetals.

Chemical Reactions

• Chemical reactions involve the breaking and forming of chemical bonds to produce new substances with different properties.
• Reactants are substances that undergo a chemical change, while products are the substances formed.
• Chemical equations represent reactions, showing the reactants on the left and the products on the right.
• Balancing chemical equations ensures that the number of atoms of each element is the same on both sides of the equation, satisfying the law of conservation of mass.
• Reactions can be classified in many ways (e.g., synthesis, decomposition, single displacement, double displacement, combustion).

Solutions

• Solutions are homogeneous mixtures of two or more substances.
• The solute is the substance dissolved, and the solvent is the substance doing the dissolving.
• The concentration of a solution expresses the amount of solute present in a given amount of solvent or solution
• Concentration can be expressed in various ways (e.g., molarity, molality, mass percent).
• Solubility is the maximum amount of a solute that can dissolve in a given amount of solvent at a specific temperature and pressure.
• Factors affecting solubility include temperature, pressure, and the nature of the solute and solvent.

Acids and Bases

• Acids are substances that release hydrogen ions (H+) when dissolved in water.
• Bases are substances that release hydroxide ions (OH−) when dissolved in water, or accept H+ ions.
• The pH scale measures the acidity or basicity of a solution.
• A pH of 7 is neutral.
• Values below 7 are acidic, and values above 7 are basic.
• Acids and bases react in neutralization reactions to form a salt and water.

Stoichiometry

• Stoichiometry is the calculation of quantities in chemical reactions.
• It involves using balanced chemical equations to determine the mole ratios of reactants and products.
• Calculations can be used to determine the amount of product formed from a given amount of reactant, or to find the amount of reactant needed to produce a certain amount of product.

Thermodynamics

• Thermodynamics is the study of energy and its transformations.
• Chemical reactions involve energy changes.
• Endothermic reactions absorb heat from the surroundings, while exothermic reactions release heat to the surroundings.
• The change in enthalpy (ΔH) measures the heat absorbed or released during a reaction at constant pressure.
• The change in entropy (ΔS) measures the disorder or randomness of a system.
• The change in free energy (ΔG) determines whether a reaction will proceed spontaneously under specific conditions.

Kinetics

• Chemical kinetics is the study of reaction rates.
• Reaction rate is the speed at which reactants are consumed or products are formed.
• Factors that affect the rate of a reaction include temperature, concentration of reactants, presence of a catalyst, and surface area of reactants.
• Reaction mechanisms describe the steps involved in a reaction.

Organic Chemistry

• Organic chemistry is the study of carbon-containing compounds.
• Organic compounds are diverse in structure and properties.
• Functional groups are specific groups of atoms that determine the properties of organic molecules.
• Hydrocarbons are the simplest organic compounds, containing only carbon and hydrogen.
• Different types of hydrocarbons exist (alkenes, alkanes, etc.)

এই কুইজে পারমাণবিক গঠন এবং রসায়নিক বন্ধনের মৌলিক ধারণাগুলি পরীক্ষা করুন। এখানে পরমাণুর উপাদান, একটি পরমাণুর পারমাণবিক সংখ্যা কীভাবে নির্ধারিত হয় এবং কি বৈচিত্র্য ইত্যাদি বিষয় অন্তর্ভুক্ত করা হয়েছে। প্রতিটি প্রশ্ন আপনাকে এই বিষয়ে গভীর ধারণা দেবার জন্য ডিজাইন করা হয়েছে।