<span>Answer: option C) pure substance.
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<span>Justification:
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<span>A sharp melting point is a characteristic of pure substances.
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<span>The pure substances are either elements or compounds: they have a unique chemical constitution (kind of elements, number of atoms of each element in the chemical formula, and same chemical bonds).
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</span><span> Other products, this is mixtures (either homogeneus or heterogeneous), being composed of different elements and compounds in different variable ratios, exhibit a range as boiling point. For example the boiling point of the gasoline is about 19°C to 200°C.
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Bromine is an element: you find it in the periodic table, with the atomic number 35, hence a pure substance.
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Answer:
A <u>mixture</u> is a material produced by mixing two or more distinct components in such a manner that there is no chemical response. Every component of purity is a <u>substance</u>. Every pure compound is a <u>substance</u>.
1) Reaction is exothermic because energy of products is less than energy of reactants
2) Energy is released because the reaction is exothermic
3) 350
4) 150
5) 500-350=150
6) 350-150=200
Answer:
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Explanation:
Answer:
detail is given below.
Explanation:
The charged particles of nucleus are protons while neutrons are neutral having no charge.
We know that an atom consist of electrons, protons and neutrons. Neutrons and protons are present inside the nucleus while electrons are present out side the nucleus. Electron has a negative charge and is written as e⁻. The mass of electron is 9.10938356×10⁻³¹ Kg . While mass of proton and neutron is 1.672623×10⁻²⁷Kg and 1.674929×10⁻²⁷ Kg respectively.
Symbol of proton= P⁺
Symbol of neutron= n⁰
The number of electron or number of protons are called atomic number while mass number of an atom is sum of protons and neutrons.
one proton contribute 1 amu to the total weight. There are 20 protons and 20 neutrons in Ca thus its atomic mass is 40 amu.
While the atomic number is 20.