Density gives mass of object per volume...... Here, density is given 8.90 g/cm3 therefore, per cubic centimeter contains 8.90 g Ni. mole of Ni = mass / atomic mass = 8.90 / 58.6934 = 0.1516 mole number of atoms: mole * 6.022 * 10^23 = 0.1516 * 6.022 * 10^23 = 0.9129 * 10^23 = 0.9 * 10^23 (approx.)
Answer: (3) ppm
Explanation: Concentration is defined as the amount of solute dissolved in a known amount of the solvent or a solution.
Parts per million (ppm) is used to express the concentration when a very small quantity of solute is present in a large quantity of the solution. It is defined as the mass of solute present in one milion 
parts by mass of the solution.
L/s is used to express flow rate.
J/g is used to express energy per unit mass.
kPa is used to express pressure.
Answer:
<h3>
Which of the following increases with the increase in the temperature in case of a liquid?</h3><h2>
<em>Va</em><em>pour</em><em> </em><em> </em><em>Pressure</em><em> </em></h2>
Explanation:
When a closed container contains liquid, higher the temperature, higher the evaporation the evaporation will be.
So Vapour Pressure should be the correct answer.
Answer:
3.5 moles Fe
Explanation:
From the equation, Reaction of 2 moles of Fe₂O₃ with 1 mole of C produces 1 mole of Fe. When excess Fe₂O₃ is used, the only liming factor is C.
The ratio of amount of C used to the amount of Fe produced is 1:1
Therefore, if 3.5 moles of C are used, 3.5 moles of Fe are also produced.
The number of transferred electrons to form the ionic bond in one formula unit of each compound is as below
NaCl = 1 electron
CaS = 2 electrons
BaO= 2 electrons
KBr=1 electrons
LIF = 1 electron
explanation
ionic bond is formed between a metal and a nonmetal . This bond is formed when electron are transferred between cation and anion. To know how many electrons transferred you look the oxidation state of the metal.
for example
in NaCl only one electrons is transferred since Na is in oxidation state of +1. Na donate the one electron to Cl to form an ionic bond. Ba is in oxidation state of 2+ and hence it donate the two electrons to O to form ionic bond.
