Answer:
0.106 mol (3s.f.)
Explanation:
To find the number of moles, divide the mass of glucose (in grams) by its Mr. Glucose has a chemical formula of C6H12O6. To find the Mr, add all the Ar of all the atoms in C6H12O6.
Ar of C= 12, Ar of H= 1, Mr of O= 16
These Ar values can be found on the periodic table.
Mr of glucose= 6(12)+ 12(1) + 6(16)= 180
Moles of glucose
= mass ÷ mr
= 19.1 ÷ 180
= 0.106 mol (3 s.f.)
<h3><u>Answer;</u></h3>
<u>= 5 M or 5 moles/liter</u>
<h3><u>Explanation;</u></h3>
At point E, 90 g of substances X are dissolved in 100 g of the solvent.
100g of the solvent is equal to 100 ml
Molarity is the number of moles of a substance in one liter of a solvent.
90 g of X are in 100 ml
But; the RFM of X = 180 g/l
Therefore; the moles of X in 90 g = 90/180
= 0.5 moles
Therefore;
0.5 moles of X are contained in 100 ml of the solvent;
Thus, molarity = 0.5 × 1000/100
=<u> 5 M or 5 moles/liter</u>
Your answer is B and the element is Carbon
So what your looking for is matching isotopes. Isotopes are elements that are the same in amount of protons but different in mass meaning different number in neutrons. Because when you add the total protons and neutrons together you get your atomic mass. So this can be written as X=said element, top number above=different atomic mass, bottom number below=atomic number. Hope this help!!
Be careful because answer A has same masses but different atomic numbers so different atoms(elements)!!!
Answer:
Cl⁻
Explanation:
Definition of atomic radii
The atomic radius is the distance between center of two bonded atoms.
Trend along period:
As we move from left to right across the periodic table the number of valance electrons in an atom increase.The atomic size tend to decrease in same period of periodic table because the electrons are added with in the same shell. When the electron are added, at the same time protons are also added in the nucleus. The positive charge is going to increase and this charge is greater in effect than the charge of electrons. This effect lead to the greater nuclear attraction. The electrons are pull towards the nucleus and valance shell get closer to the nucleus. As a result of this greater nuclear attraction atomic radius decreases.
Trend along group:
In group by addition of electron atomic radii increase from top to bottom due to increase in atomic number and addition of extra shell.
In this way Cl⁻ will have the largest atomic radii because one extra electron is added and its atomic number is already greater than fluorine.
Answer:
it is an exothermic reaction
Explanation:
exothermic reactions have a negative ∆H
i.e, product of the reaction is less that the reactants of the reaction
(Note : ∆H= products - reactants), that's why it's exothermic
