Question

Распределите буквенные обозначения предложенных явлений на физические и химические и укажите их общий признак .а)образование накипи б)плавление металла с)гниение листьев д)пожелтение листьев и)образование инея ж)дыхание п)появление радуги.

Answer 1

Физические- плавдение металла, образование инея, появление радуги. Общий признак- агрегатные состояния   
химические- остальные, кроме дыхания. Общий признак- изменение цвета.

Answer 2

Classification of Phenomena into Physical and Chemical and their Common Characteristics

a) The formation of scale - chemical phenomenon. Scale formation occurs when minerals in water react with surfaces, such as pipes or heating elements, and form a hard, crusty deposit. This is a chemical process involving the formation of new compounds [[1]].

b) Melting of metal - physical phenomenon. Melting is a physical process in which a solid metal changes into a liquid state due to the application of heat. It does not involve any chemical reactions or the formation of new substances [[2]].

c) Decay of leaves - chemical phenomenon. The decay or decomposition of leaves is a chemical process known as rotting or putrefaction. It involves the breakdown of organic matter by microorganisms, such as bacteria and fungi, resulting in the release of various gases and the formation of new compounds [[3]].

d) Yellowing of leaves - physical phenomenon. The yellowing of leaves is primarily a physical change caused by the loss of chlorophyll, the green pigment responsible for photosynthesis. It can be due to factors such as aging, nutrient deficiencies, or environmental stress. No chemical reactions or new substances are formed during this process [[4]].

e) Formation of frost - physical phenomenon. The formation of frost, or the deposition of ice crystals on surfaces, occurs when water vapor in the air condenses directly into ice without going through the liquid phase. It is a physical process driven by temperature and humidity conditions [[5]].

f) Respiration - chemical phenomenon. Respiration is a chemical process that occurs in living organisms, including plants and animals. It involves the breakdown of organic molecules, such as glucose, to release energy in the form of ATP (adenosine triphosphate). This process involves various chemical reactions, such as glycolysis and the Krebs cycle [[6]].

g) Appearance of a rainbow - physical phenomenon. The appearance of a rainbow is a physical phenomenon caused by the interaction of sunlight with water droplets in the atmosphere. It is a result of the dispersion, refraction, and reflection of light, creating a colorful arc in the sky [[7]].

The common characteristic of chemical phenomena is the involvement of chemical reactions and the formation of new substances. Physical phenomena, on the other hand, do not involve chemical reactions and the formation of new substances. They are primarily related to changes in physical properties, such as state, shape, or appearance, without altering the chemical composition of the substances involved.

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