The Science Curriculum in Primary and Lower Secondary Grades

The science curriculum in Grades 2 to 6 treats science as one general integrated subject. In Grade 2, science is known as the World Around Us, and in Grades 3 to 6, it is known as Man and Nature.

In Grade 4, Man and Nature is structured according to three distinct subject areas in physical, chemical, and biological modules. The main requirements for students in Grades 4 and 8 are summarized according to the National Education Content Standards, which are guiding and compulsory documents for all Bulgarian schools.

The science programs of study prescribe:

Content fields, called content cores
National attainment targets, or expected learning outcomes, by content field
Science content by topic, concepts, context, activities, and interdisciplinary links
Specific methods and forms of assessment
Recommended teaching methods and guidelines

Science content standards, expected outcomes, and core topics for students at the end of Grade 4 are presented in Exhibit 2.

Exhibit 2: Science Learning Outcomes at the End of Grade 4

Area of Content / Competency	Expected Learning Outcomes
Substances, Bodies, and Organisms	Distinguish substances by their properties and uses Differentiate nonliving from living things by their characteristics Give examples of major groups of organisms living in water, in soil, and on land, and their adaptive characteristics Classify plants (e.g., trees, bushes, and grasses) and animals (e.g., mammals, birds, reptiles, fish, and insects) Know that the Earth is a planet in our solar system and the Sun is the main source of heat and light for the Earth
Phenomena and Processes in Nature	Name the basic life processes in organisms: nutrition, movement, growth, and reproduction Give examples of the need for energy in living organisms, everyday life, and industry Explain where the energy for living things comes from and how it is used Identify the three water states and explore water state changes through heating and cooling Describe the motion of bodies and organisms (i.e., the movement of everyday things and animals in certain habitats, and forces that cause motion) Recognize the seasons and seasonal changes in nature
Man and Health	Describe human organs and basic life processes in the human body Understand principles of hygiene and personal health (e.g., nutrition, infectious and noninfectious diseases, and general health) Identify human actions that can affect the balance of nature Recognize that disturbing the balance of nature can impact human health Identify possible courses of action for environmental protection Identify substances harmful to human health Identify common environmental pollutants
Observation, Experimentation, and Inquiry	Share observations of living and nonliving things in the natural world (following a given plan or guidelines) Carry out simple experiments with objects, substances, and plants Measure the temperature of air, water, and the human body Compare sounds by their power and understand that very loud sounds can be harmful to people

In Grade 8, the science curriculum is split into three distinct subjects: Physics and Astronomy, Chemistry and Environmental Protection, and Biology and Health Education. Together, the World Around Us (Grade 2), Man and Nature (Grades 3 to 6), Physics and Astronomy, Chemistry and Environmental Protection, and Biology and Health Education (Grades 7 to 8) cover the core educational domains of the natural sciences and ecology.

Geography is taught as a component of Geography and Economics, which is pertinent to the educational domains of the social sciences, civic education, and religion.

Science content standards, expected outcomes, and core topics for students in Grade 8, in Physics and Astronomy, Chemistry and Environmental Protection, and Biology and Health Education, are presented in the following exhibits. Geography content standards, expected outcomes, and core topics for students in Grade 8 can be found on the website of the Ministry of Education.³

Exhibit 3.1: Grade 8 Physics and Astronomy Topics

Area of Content / Competency	Topics
Movement and Forces	Mechanical movement—Average and instantaneous velocity, acceleration, and linear motion laws Principles of mechanics—Gravitational force and weight, normal force, friction, applications of Newton’s second law, and action and opposite reaction Mechanical work and energy—Mechanical work and power, kinetic and potential energy, and mechanical energy Equilibrium of objects, and simple machines—Stable and unstable equilibrium, center of gravity, and laws of the lever, the pulley, and the inclined plane Fluid mechanics—Common properties of liquids and gases, the application of Pascal’s law and the formula for hydrostatic pressure to explain how hydraulic machines operate, and water and mercury manometers
Energy	Thermal energy—Thermal motion, thermal equilibrium, internal energy and temperature, and Celsius to Kelvin temperature conversion Conservation of energy—Quantity of heat, heat transfer, first law of thermodynamics as a law of conservation of energy, and specific heat capacity Ideal gases—Isothermal, isobaric, and isochoric processes, and the ideal gas law State of matter changes—Boiling, condensation, melting and freezing, including everyday examples, and specific temperature of fusion and evaporation Heat engines—The calculation of the energy conversion efficiency of heat engines, the Otto cycle and ecological problems caused by internal combustion engines, and the evaluation of the thermal efficiency of heat engines and thermal pollution
Observation, Experimentation, and Inquiry	Student skill objectives: Using information on mechanical and thermal processes from a variety of sources (e.g., tables, schematics, pictures, videos, and software) Performing observations and experiments Working with calorimeters, thermometers, scales, manometers, etc. Reporting results of measurements and calculating physical quantities

Exhibit 3.2: Grade 8 Chemistry and Environmental Protection Topics

Area of Content / Competency	Topics
Classification of Matter and Nomenclature	Properties of matter—Common properties of metals and nonmetals, differences and similarities between metals of the alkaline group and nonmetals of the halogen group, and the relationship between the position of elements in the periodic table and their properties Classes of inorganic substances—Metals, nonmetals, oxides, hydroxides, and acids; the relationship between different classes of compounds
Structure and Properties of Chemical Substances	Group IIA—Properties and biological importance of magnesium and calcium, calcium oxide, hydroxide, and carbonate Group VIA—Properties of sulfur, its oxides, sulfuric acid and sulfates, and acid rain, including its causes and impact on the environment Aluminum—Properties of aluminum and its compounds Aqueous solutions of acids, bases, and salts—Definition, ionization
Chemical Processes	Behavior of metals—Activity series, redox processes and their applications, and oxidizing and reducing agents
Uses of Substances	Organic substances—Examples of hydrocarbons and organic compounds containing oxygen, and their uses: methanol, ethanol, glycerol, acetone, and acetic acid; the composition of petroleum and natural gas; examples of plastics and their uses: polyethylene, polyvinyl chloride, and polystyrene; examples of chemical fibers and their uses: cotton, wool, silk, nylon, and polyester Organic substances in living organisms—Carbohydrates: glucose, sucrose, starch, and cellulose; the origin and properties of fats and oils; and the composition and biological role of proteins
Experimentation and Inquiry	Student skill objectives: Testing physical quantities and relationships (mass, amount of substance, molar mass, molar volume, and mass fraction) Planning simple chemistry experiments Performing experiments to identify sulfates, acids and bases, and calcium hydroxide Observing safety rules while carrying out experiments

Exhibit 3.3: Grade 8 Biology and Health Education Topics

Field of Content / Competency	Topics
Structure, Living Processes, and Classification of Organisms	The animal kingdom: Phylum–Chordates Superclass–Fish Class–Amphibians Class–Reptiles Class–Birds Class–Mammals
The Human Organism: Structure, Living Processes, and Hygiene	The place of humans within the mammal class—Classify according to the following taxa: Order–Primates, Family–Hominids, Genus–Homo, Species–Homo Sapiens; list certain distinctive features of Homo Sapiens in relation to the mammal class; recognize humans as biosocial beings The human organism: structural levels of organization—Cells, tissues, organs, and organ systems Skin—Structure, functions, skin diseases, and hygiene Musculoskeletal system—Structure, functions, disorders and diseases, and a healthy balanced lifestyle (sports and tourism) Cardiovascular (circulatory) system—Structure, functions, blood composition, heart and vascular diseases and disorders, emergency help for severe bleeding, and risk of blood borne infections Digestive system—Structure, functions, healthy food and nutrition, digestive diseases and disorders, and risks of food, alcohol, and drug abuse on health Excretory system—Structure, functions, and disorders and diseases Respiratory system—Structure, functions, disorders and diseases, and the impact of air pollution, tobacco smoking, and narcotics on health Reproductive system—Female and male reproductive system, stages of embryogenesis, disorders and diseases, sexually transmitted infections, safe sex, and contraception Nervous system—Reflex, reflex arc, analyzations, organs (brain, spinal cord, and nerves), disorders and diseases, and risks of alcohol and drug abuse Endocrine system—The pituitary, thyroid, and adrenal glands, the pancreas, ovaries, and testes; the role of hormones in the regulation of physiological processes, and disorders and diseases
Organisms and Habitat	The interaction of organisms and their habitat Humans as organisms—The role of humans in the natural world, the negative consequences of certain human activities, the need for education about the natural world and the proper use of its resources, and the human role in the preservation of biodiversity
Observation, Experimentation, and Inquiry	Student skill objectives: Observing objects and phenomena in nature and the school laboratory Checking blood pressure (i.e., measurement and normal ranges) Performing first aid Practicing rules of hygiene