Answer : The correct answer is Option D.
Explanation:
Ores are defined as natural occurring substance from which metals and another mineral are extracted.
Bauxite is primary ore of an aluminium metal. it doesn't have definite or specific chemical composition. This is because it contains mixture of hydrous aluminum oxide, aluminum hydroxides, insoluble materials like hematite, quartz ,geothite ,magnetite etc.
From the given options the most appropriate statement which is correct about the bauxite is 'It does not have a definite chemical composition'.
Hence, the correct option Is (D).
Answer:
It is higher.
Explanation:
The amplitude of a wave that carries more energy is usually higher.
The energy carried by a wave is related to the amplitude in such a manner that it is proportional to the square amplitude.
Amplitude is the maximum vertical displacement of a wave moving along its path.
- Energy of wave and its amplitude are directly proportional to one another.
- If the energy of wave is doubled, the amplitude is quadrupled.
- So, the higher the energy of a wave, the more its amplitude.
Answer:
Pb(s), Sn(s), Cu(s), Fe(s), Al(s)
Explanation:
The specific heat (Cp) of a substance is defined as the heat required per unit of mass to raise the temperature in 1°C.
Thus, the substance with the larger Cp will need more energy to reach a temperature and vice versa.
Based on this information, the fastest metal to reach 80°C will be Pb -lowest Cp-, then Sn, Cu, Fe and Al.
From 1 to 5:
<em>Pb(s), Sn(s), Cu(s), Fe(s), Al(s)</em>
Answer:
mass is 4.57 g
Explanation:
Ca(OH)₂ solution consists of Ca(OH)₂ solute molecules and solvent and we are asked to find the mass of Ca(OH)₂ in the solution
number of moles of Ca(OH)₂ is - 0.0787 mol
molar mass of Ca(OH)₂ is - 58.093 g/mol
we can use the following equation
number of moles = mass of Ca(OH)₂ / molar mass of Ca(OH)₂
rearranging the equation
mass of Ca(OH)₂ = number of moles x molar mass
mass = 0.0787 mol x 58.093 g/mol = 4.57 g
mass of Ca(OH)₂ is 4.57 g
<u>Answer: </u>The correct statement is X is the effective nuclear charge, and it increases across a period.
<u>Explanation:</u>
We are given that:
X = number of protons − number of core electrons
Effective nuclear charge is defined as the actual nuclear charge (Z = number of protons) minus the screening effect caused by the electrons present between nucleus and valence electrons. These electrons are the core electrons.
The formula used for the calculation of effective nuclear charge given by Slater is:
where,
= effective nuclear charge
Z = atomic number or actual nuclear charge or number of protons
= Screening constant
The effective nuclear charge increases as we go from left to right in a period because nuclear charge increases with no effective increase in screening constant.
Hence, the correct answer is X is the effective nuclear charge, and it increases across a period.