Something made of pure iron<span> is softer </span>than steel<span> because the atoms can slip over one another. If other atoms like carbon are added, they are different from </span>iron<span> atoms and stop the </span>iron<span> atoms from sliding apart so easily. This makes the metal </span>stronger<span> and </span>harder<span>.</span>
Answer:
Endothermic reaction chemical equation
Reactnt A + Reactant B + Heat (energy) ⇒ Products
Exothermic reaction chemical equation
Reactnt A + Reactant B ⇒ Products + Heat (energy)
Explanation:
Endothermic Reaction
An endothermic reaction is a reaction that reaction that requires heat before it would take place resulting in the absorption of heat from the surrounding that can be sensed by the coolness of the reacting system
An example of an endothermic reaction is a chemical cold pack that becomes cold when the chemical and water inside it reacts
Exothermic Reaction
An exothermic reaction is one that rekeases energy to the surroundings when it takes place. This is as a result of the fact that the combined heat energy of the reactants is more than the chemical heat energy of the products. An example of an exothermic reaction is a burning candle
Answer:
Nuclear fusion plays an important role in making elements that are heavier than helium.
Explanation:
Nucleosynthesis is the process by which new atomic nuclei are created from pre-existing nucleons (protons and neutrons) and nuclei. According to current theories, the first nuclei were formed a few minutes after the Big Bang, through nuclear reactions in a process called Big Bang nucleosynthesis.
In order to synthesize a new element, there must be a change in the number of protons. We should remember that elements are known by the number of their protons as it represents their atomic number.
Elements heavier than helium are formed by nuclear nucleosynthesis in which nuclear fusion plays a very crucial role as typified by the equations shown in the question.
Answer:
c) Tìm những chất có hàm lượng đồng bằng nhau trong 4 chất : CuO, Cu2O, CuS, Cu2S.
Explanation:
