Answer:
C
Explanation:
The nuclear reactions involves the nuclei of the atoms, large amount of energy will be involved and some of the mass is converted into energy.
Explanation
Nuclear reactions are reactions which leads to change in the nuclei of the atoms.
The nuclear reaction occur between the nuclei of two atoms or between nuclei and other particles of two atoms.
The product formed will be different from the reactants.
The difference in the mass of the products and reactants are generally converted into energy.
In some nuclear reactions like nuclear fusion reaction, large amount of energy is required to collide the nuclei of two heavy elements to undergo nuclear chain reaction.
Be
Ca
Ba
Sr
Answer:
none
Explanation:
it's Fr. which is francium.
Explanation:
An atomic radius is defined to be one-half the distance between the nuclei of two atoms, assuming a spherical atom since, according to the quantum mechanical model of the atom, electrons are located within a probability cloud surrounding the nucleus which has no sharp boundary.
Notice that, in general, there are two main trends of atomic radii in the Periodic Table of Elements.
The first trend illustrates that atomic radii increase when going down a group in the periodic table. This is because when moving downwards in a group, every subsequent atom gains an additional principal energy level, which leads to electron shielding. Electron shielding refers to the decreased attraction between the electrons that occupy the higher principal energy level and the nucleus of the atom due to the shielding of electrons in the lower principal energy level.
The second trend outlines that atomic radii decrease when going across the period from left to right. For elements within a period, individual electrons occupy the same principal energy level. Likewise, when an electron is added, a new proton is also added to the nucleus, providing the nucleus with a stronger positive charge and hence leading to a higher effective nuclear charge. This increase in nuclear attraction pulls the electrons closer towards the nucleus, leading to a decrease in atomic radius.
Therefore, given the option between beryllium, calcium, barium, and strontium, the element with the largest atomic radius is barium since all the elements given are in Group II, however, barium is the element furthest down the group and therefore have electrons occupying the highest principal energy level compared to other elements.
Answer:pH = 2.96
Explanation:
C5H5N + HBr --------------> C5H5N+ + Br-
millimoles of pyridine = 80 x 0.3184 =25.472mM
25.472 millimoles of HBr must be added to reach equivalence point.
25.472 = V x 0.5397
V =25.472/0.5397= 47.197 mL HBr
total volume = 80 + 47.197= 127.196 mL
Concentration of [C5H5N+] = no of moles / volume=
25.472/ 127.196= 0.20M
so,
pOH = 1/2 [pKw + pKa + log C]
pKb = 8.77
pOH = 1/2 [14 + 8.77 + log 0.20]
pOH = 11.0355
pH = 14 - 11.0355
pH = 2.96
Answer:
49.4 mol Oxygen
Explanation:
Mg(NO3)2 ----- 6 O
1 mol 6 mol
8.24 mol x mol
x = 8.24*6/1 = 49.44 mol ≈ 49.4 mol Oxygen
Answer: The limiting reactant is magnesium and mass of excess reactant present in the vessel is 96.35 grams.
Explanation:
To calculate the number of moles, we use the equation:
.....(1)
Given mass of magnesium = 41.0 g
Molar mass of magnesium = 24 g/mol
Putting values in equation 1, we get:
Given mass of iron(III) chloride = 175.0 g
Molar mass of iron(III) chloride = 162.2 g/mol
Putting values in equation 1, we get:
The chemical equation for the reaction of magnesium and iron(III) chloride follows:
By Stoichiometry of the reaction:
3 moles of magnesium reacts with 2 moles of iron(III) chloride
So, 1.708 moles of magnesium will react with = of iron(III) chloride
As, given amount of iron(III) chloride is more than the required amount. So, it is considered as an excess reagent.
Thus, magnesium is considered as a limiting reagent because it limits the formation of product.
Moles of excess reactant left (iron(III) chloride) = [1.708 - 1.114] = 0.594 moles
Now, calculating the mass of iron(III) chloride from equation 1, we get:
Molar mass of iron(III) chloride = 162.2 g/mol
Moles of iron(III) chloride = 0.594 moles
Putting values in equation 1, we get:
Hence, the limiting reactant is magnesium and mass of excess reactant present in the vessel is 96.35 grams.
C=46.67%, H=4.48%, N=31.10%, O=17.76%.
The molecular weight is 180.16g/mol.
Answer:
Explanation:
Hello!
In this case, since the determination of an empirical formula is covered by first computing the moles of each atom as shown below:
Now, we divide each moles by the fewest moles (those of oxygen), to obtain the subscripts in the empirical formula:
Thus, the empirical formula, taken to the nearest whole subscript is:
Whose molar mass is 180.16, therefore the empirical formula is the same to the molecular one.
Best regards!