Answer:
B. It undergoes a physical change.
Explanation:
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In this case, since we know that chemical changes lead to the formation of new atoms and/or compounds due to the bonds rearrangement of the initial substances and the physical changes occur without changing the composition of the initial substances, we can infer that, since melting is a process that changes the phase of matter from solid to liquid without changing the identity of the initial substance, the answer to this question would be B. It undergoes a physical change. because the other options describe chemical changes.
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answer: 3g. 17kg+3 ÷ 0.25
D. Wind will always move from areas of high pressure to low pressure. It's the reason we have weather, or one of them. Temperature is another factor.
B. That is the definition of the greenhouse effect.
It is a element.
Pure substances includes either compunds, or elements. Elements are the simplest form of pure substance, they only consist of one kind of atoms. On the other hand, compounds contains two or more elements that are chemically combined together. Although you couldn't separate a compound by physical methods like filtration, but you can seperate them with chemical methods such as heating or electrolysis, using electricity.
Therefore, since compounds can be broken down eventually, so, the answer will be element.
Answer:
THE MOLARITY OF SODIUM CHLORIDE IN THE CONTAINER IS 0.3846 M.
Explanation:
Molarity of a solution is the number of moles of solute per dm3 of solution.
Mass concentration = Molar concentration * Molar mass
1. calculate the mass concentration;
Mass conc. = 45 g in 2 L
= 45 g in 2 dm3
In 1 dm3, the mass will be 45 / 2
= 22.5 g/dm3 of NaCl.
2. Calculate the molar mass;
(Na = 23, Cl = 35.5)
Molar mass = ( 23 + 35.5 ) g/mol
Molar mass = 58.5 g/mol
3. calculate the molarity
Molarity = mss concentration / molar mass
Molarity = 22.5 g/dm3 / 58.5 g/mol
Molarity = 0.3846 mol/dm3 of NaCl.
The molarity of sodium chloride in the container is 0.3846 mol/dm3
