Answer:
MIXTURE
Explanation:
A mixture is a substance composed of a combination of other different substances. These component(s) of a mixture are physically combined, meaning that there is no chemical linkage between the individual components/constituents of a mixture.
This is the case of the gravel described in this question. The components of gravel can be separated using physical means because they are not chemically bonded to one another, hence, no chemical reactions are needed to separate different parts of gravel into pure substances. This makes gravel a MIXTURE.
Answer:
C. Atoms have isotopes of an element have different numbers of protons.
Explanation:
The isotopes are the variation in the number of neutrons (neutral charge), with increases the weight of the atom, so the first one, is related to this one.
Answer:
1.8321 kg
Explanation:
The given 1 kg of coal contains 50% of the carbon atom by mass. Thus, mass of carbon in coal is 
Also, 1 kg = 1000 g
So, mass of carbon = 500 g
The formula for the calculation of moles is shown below:
Molar mass of carbon = 12.0107 g/mol
Moles of methanol = 500 g / 12.0107 g/mol = 41.6295 moles
Considering the reaction:
From the reaction,
1 mole of C react to form 1 mole of 
So,
41.6295 moles of C react to form 41.6295 moles of
Moles of = 41.6295 moles
Molar mass of = 44.01 g/mol
So, Mass = Moles × Molar mass = 41.6295 moles × 44.01 g/mol = 1832.1143 g
Also, 1g = 0.001 kg
<u>So, amount of released = 1.8321 kg</u>
Atomic radius is the distance from the nucleus to the last valance electron up to which the effect nucleus can be felt. The size of the atom depends on the Electrostatic interaction between nucleus and electron. Number of atomic orbitals present. With the increase in numbers of orbitals down the group the size of the atom increases. Again, as the numbers of electrons increases in the period ,the electrostatic interaction between nucleus and electron increases along the period. Therefore, size of atoms decreases along the period.
As expected the element with highest atomic radius is the last element of group 1 , Which is FRANCIUM ( Fr)
Answer:
ΔH > O and ΔH > TΔS
Explanation:
When a reaction is non-spontaneous even though the standard entropy change of the reaction is large and positive the reason is the reaction is highly endothermic and dominates the term TΔS in the standard Gibbs free energy expression:
ΔG = ΔH-TΔS
Remember that for an endothermic reaction to be spontaneous ΔG < 0 and this can occur only if the term TΔS is greater than ΔH. This is not the case for quartz which requires a good quantity of energy to overcome its crystaline 3D lattice in which the oxygen are shared between 2 silicon atoms.
