Question

какие из этих явлений нельзя отнести к химическим ??? плавление льда. ржавление железной проволки . прокисшее молоко . снятие стружки с доски . растворение соды .помогите кто знает пожалуйста зарание спасибо . а если я что знать буду то я помогу вам ...

Answer 1

плавление льда снятие струдки с доски

Answer 2

Плавление льда - физическое

Снятие стружки с доски - физическое

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Остальные химические явления (при ржавлении происходит коррозия стали при взаимодействии с водой, появляется ржавчина. При скисании молока происходит изменение запаха, осадок, это и является признакоми химических реакций)

Answer 3

Phenomena that cannot be attributed to chemical reactions

There are several phenomena listed, and we need to determine which ones cannot be attributed to chemical reactions. Let's analyze each one:

1. Melting of ice: The melting of ice is a physical change, not a chemical reaction. It occurs when heat is applied to ice, causing it to change from a solid to a liquid state. This change is reversible, and no new substances are formed during the process.

2. Rusting of iron wire: The rusting of iron wire is a chemical reaction. When iron reacts with oxygen and moisture in the air, it forms iron oxide, commonly known as rust. This process is irreversible and involves the formation of a new substance.

3. Spoiled milk: The spoilage of milk is primarily caused by the growth of microorganisms, such as bacteria and fungi. While these microorganisms can produce chemical changes in the milk, the spoilage itself is not considered a chemical reaction. It is a biological process that leads to the degradation of milk proteins and the production of compounds that give off unpleasant odors and flavors.

4. Shaving wood off a board: Shaving wood off a board is a physical process known as planing. It involves the removal of thin layers of wood from the surface of the board using a sharp tool. This process does not involve any chemical reactions; it only changes the physical shape and size of the wood.

5. Dissolving baking soda: Dissolving baking soda in water is a physical process called dissolution. It occurs when the individual particles of baking soda separate and disperse in water, forming a homogeneous mixture. No chemical reactions take place during this process.

Based on the analysis above, the phenomena that cannot be attributed to chemical reactions are melting of ice and shaving wood off a board. These are physical processes that do not involve the formation of new substances through chemical reactions.

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