Answer:
Isotopes are atoms of the same element that have different numbers of neutrons but the same number of protons and electrons. The difference in the number of neutrons between the various isotopes of an element means that the various isotopes have different masses.
The density of a material is its unique property by which a unknown material can be identified and also the impurity (if present) in a material can be concluded. Mathematically the density can be expressed as-
. Thus from the mathematical expression we can say that the density is the mass per unit volume of a material. Here the density of ethanol is given 0.789 g/mL. Thus the weight of the 1 mL ethanol is 0.789g. Thus the weight of the 125 mL of ethanol will be (125×0.789) = 98.625 g.
Answer:
Explanation:
When group 7 elements react , their atoms gains one electron into their highest occupied energy level ( outer shell) to form single negative - charged ion .
As you move down the group , the outer shells get increased i.e an additional electron shell is added thereby increasing the atomic radius of the atom. The electrons in the outer shell move further away from the nucleus as we go down the group .
Therefore the force of attraction between the shells and nucleus is decreased .
This makes attracting an extra electron difficult . And so ability of the atom to attract electron to fill the outermost shell reduces which means the reactiveness of the atom reduces.
False. They may bond with Alkaline Earth metals
Answer: The molarity of solution is 0.453 M
Explanation:
Molarity of a solution is defined as the number of moles of solute dissolved per liter of the solution.
where,
n = moles of solute
= volume of solution in ml
moles of 
= 
Now put all the given values in the formula of molality, we get
Therefore, the molarity of solution is 0.453 M
