<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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The balanced equation for the neutralisation reaction is as follows
Ca(OH)₂ + H₂SO₄ ---> CaSO₄ + 2H₂O
stoichiometry of Ca(OH)₂ to H₂SO₄ is 1:1
equivalent number of acid reacts with base
number of H₂SO₄ mol reacting - 2 mol
according to molar ratio of 1:1
number of Ca(OH)₂ mol = number of H₂SO₄ moles
therefore number of Ca(OH)₂ moles required - 2 mol
Answer:
1. aa
2. They have similar DNA
Explanation:
1. According to the question 1, wrinkled seeds (A) are dominant over round seeds (a) in pea plants. This means that, based on the law of dominance proposed by Mendel, wrinkled seeds will be expressed over round seeds in a heterozygous state (Aa).
However, since the round seed phenotype is a recessive trait, it will only be expressed when the alleles for round seeds (a) are the same in the gene i.e. aa genotype.
2. Based on the information in question 2, Ricky, who is working on a family tree for his school project, realizes that his close relatives all look similar in the pictures he collected. This is possible because of the SIMILARITY OF THEIR DNA (genetic material). Note that, relatives are connected by the genes that are inherited from one another, hence, they possess a similar DNA, which is the most valid reason for the resemblance.
Compare them accordingly with the formula of E=hc/wavelength