<span>You can answer this question by getting the atomic number and atomic mass of Oxygen from a periodic table. There you will find that the atomic number is 8, that means, by definition, that it has 8 protons. This is, because atomic number is defined as the number of protons of an element. Given that the atom is neutral, that implies that the atoms have the same number of electrons than protons. So you already know that the oxygen atoms has 8 protons and 8 electrons. The number of neutrons can vary, which is what defines the isotopes. Given that the atomic mass of oxygen is 15.999, that means that most atoms of oxygen has 8 neutrons (8 protons +8 neutrons = 16 atomic mass). But you can not be sure that a specific atom of oxygen has 8 neutrons, nevertheless, given that the other options are discarded (because they do not have 8 protons and 8 electrons), the only correct answer is the option A. 8 protons, 8 electrons, and 8 neutrons.</span>
Answer:
Physical properties can be observed, described, and measured without changing the material. ... To find the volume of a solid, pour liquid in a graduated cylinder and let a solid object sink in the liquid and measure how much volume is in the solid
<u>Answer</u>:
By tracking oxidation numbers we can identify the number electron in the atom
<u>Explanation</u>:
Tracking of electrons helps us to know when and how many electrons get transferred from one atom to other atom . Oxidation referred as the “loss of one or more electrons” by an atom. When the oxidation number of an element increases, there is a loss of electrons and that element is being oxidized. Oxidation numbers are usually written with the sign (+plus or −minus) followed by the magnitude, which is the opposite of charges on ions. In their elemental stage oxidation number of an atom is zero.
Answer:
a) 7.0.
b) Nickel sulfate hepta hydrate.
c) 280.83 g/mol.
d) 44.9%.
Explanation:
<u><em>a) What is the formula of the hydrate?</em></u>
The mass of the hydrated sample (NiSO₄.xH₂O) = 5.0 g,
The mass of the anhydrous salt (NiSO₄) = 2.755 g,
The mass of water = 5.0 g - 2.755 g = 2.245 g.
∴ no. of moles of water = mass/molar mass = (2.245 g)/(18.0 g/mol) = 0.1247 mol.
∴ no. of moles of anhydrous salt (NiSO₄) = mass/molar mass = (2.755 g)/(154.75 g/mol) = 0.0178 mol.
∴ water of crystallization in the sample (x) = no. of moles of water/no. of moles of anhydrous salt (NiSO₄) = (0.1247 mol)/(0.0178 mol) = 7.0.
<u><em>b) What is the full chemical name for the hydrate?</em></u>
The name of the salt (NiSO₄.7H₂O) is Nickel sulfate hepta hydrate.
<u><em>c) What is the molar mass of the hydrate? </em></u>
(NiSO₄.7H₂O)
The molar mass = molar mass of NiSO₄ + 7(molar mass of H₂O) = (154.75 g/mol) + 7(18.0 g/mol) = 280.83 g/mol.
<em><u>d) What is the mass % of water in the hydrate?</u></em>
The mass % of water = (mass of water)/(mass of hydrated sample) x 100 = (2.245 g)/(5.0 g) x 100 = 44.9%.
