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Chemistry answers to 38 questions

Answer: 4. the application of knowledge gained. Four main principles govern the scientific method. They are: • Making observations • Creating a hypothesis from the observation • Testing the hypothesis • Draw reasonable conclusions from the hypothesis Three of the…
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It is important to keep high acid food away from the coated tub because there would be a reaction between the food high in acid and the zinc-coated tub. The outcome of the reaction is Zinc salt which would contaminate…
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Answer: 2. CaO (s) + CO2 (g) → CaCO3 (s) and 4. PbCO3 (s) → PbO (s) + CO2 (g) In (2), limestone is decomposed under heating to give rise to quicklime and CO2, while (4), is the thermal decomposition…
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Even though acids and bases are fundamentally different in nature, there are some similarities between them. For example, both acids and bases cause a chemical reaction when applied to litmus paper -acid changes blue litmus paper to red, while bases…
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Answer: A. Periods. Explanation: The periodic table is divided into rows and columns. The rows run across the table from one end to the other and are called periods. The columns run from the top of the periodic table to…
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Answer: C. Tertiary structure. Explanation: The overall three-dimensional folded structure of a polypeptide is referred to as the tertiary structure. The structure is due to the relationship between the R-groups of the amino acids that constitute the building blocks of…
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Answer: B. Phosphorus is not abundant in the atmosphere, it comes mostly from the land and ocean. Explanation: The phosphorus cycle differs from other cycles because it does not particularly cycle through the atmosphere, unlike carbon. The phosphorus that exists…
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Answer: D. Energy. Explanation: Unlike carbon, nitrogen, water, and phosphorus which can be converted and recycled as it moves from one level of an ecosystem's food chain to another, energy can only be transferred from one form to another, but…
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Answer: High-spin complex ions: 4)[Co F6 ] 3- four unpaired e-'s 5)[Mn (H2O) 6 ] 2+ five unpaired e-'s Low-spin complex ions: 1) [Fe (CN)6 ] 4- no unpaired e- 2) [Fe (CN)6 ] 4- one unpaired e- 3) [Co…
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Proteins are polymers, not lipids since they have long sequences of amino acids. Lipids are known for their single structure made of glycerol and three fatty acids. A polymer is a large molecule made of several monomers. A monomer is…
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A mole is a unit of measurement that is assigned to the quantity of any substance. It is the molarity of a given substance, and it is often measured in mols per meter. A molecule is a group of atoms…
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Iron has 2 valence electrons. Valence electrons refer to the number of electrons that an element has in its outermost shell. This outermost electron is referred to as the ionization power of an atom. This means the number of electrons…
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Answer: D. Sugar burns when heated on a skillet. A chemical reaction is one that when it occurs, new substances are formed, and it is not easily reversible by simple chemical processes. A. When sugar dissolves in water, no new…
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D. Nitrogen. Greenhouse gases are gases that transfer heat from the sun's heat in one-way traffic. As these gases increase, they expand, causing heat to enter the Earth through the atmosphere, but they refuse to allow these radiations to leave…
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The correct answer is B. They are consumed by the reactions they catalyze
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The most reactive group of elements on the periodic table are elements in Group 1. They are highly reactive because the distance between the outermost electron and the nucleus increases as you move further down the group. These elements are…
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Despite the sharp variations in their functions, acids and bases have a few similarities. a. Both acids and bases are water-soluble. They dissolve in water to become diluted. b. Both acids and bases are good conductors of electricity. c. When…
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An atom is the smallest component of an element, while a molecule is made up of two or more atoms. While atoms comprise protons, neutrons, and electrons, molecules comprise two or more atoms that are combined chemically. Atoms cannot be…
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Hello! As a rule, chromosomes become visible during prophase, so, the correct version is B. Prophase is the first and the longest phase of mitosis, and during this stage nuclear membrane breaks down and chromosomes become visible.
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Correct answer is B - dipole-dipole. Dipole-dipole interaction is much stronger than London dispersion forces, but weaker than covalent or ionic bonds. It equals 5-10 kJ per mole.
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In this case, you should use the formula for finding the maximum number of stereoisomers for a compound: N max = 2m, where n = the number of chiral centers So, the calculations for your example will look as follows:…
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As a rule, we use roman numerals in the name of a compound when a metal cation forms two ions with different states of oxidation. For instance, Cu can form two different ions - Cu+ and Cu 2+. Combining with…
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Atomic mass is a mass of a single atom, it can be calculated as a sum of neurons and protons in the atom. In turn, a molar mass is a mass of a substance (in grams) divided by the number…
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Here's the answer: When an atom emits an alpha particle, it transforms into a different element, therefore, its atomic number will be reduced by two.
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Water can dissolve the ionic compound because of the diference between its hydration and lattice energy.
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The given mass of an element can be found using Avogadro's number, which equals 6.02214076 × 1023 mol-1 and gives you one mole of anything. 1. You determine the molar mass of the element. 2. Then, you divide the given…
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Correct answer is 1. MgO is expected to have the highest lattice energy.
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Hi there! BrCl3 is definitely a polar molecule, it is evident from its T-shaped molecular geometry.
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No of protons - 29 No of neutrons - 35 No of electrons - 29 Explanation: Since the atomic number of copper is 29, the number of protons equals 29 as well. Since the atom is neutral, the number of…
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First, you should write a molecular equation: MgCl2(aq) + 2NaOH(aq) ==> Mg(OH)2(s) + 2NaCl(aq) Then, the net ionic reaction will equal: Mg^2(aq) + 2OH^-(aq) ==> Mg(OH)2(s)
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