According to atomic theory: a. the nucleus is positively charged.
b. the nucleus contains both charged and uncharged particles.
c. the electrons contribute very little to the total mass of the atom.
d. the electrons are located in the atomic space outside the nucleus.
e. all of these

Answer:

Ice is Less Dense than water

Explanation:

If you put ice in water the ice won't sink to the bottom because water is denser then ice.

:)

Bromine is a chemicalelement with symbol Br and atomic number 35. It is a halogen. The element wasisolated independently by two chemists, Carl Jacob Löwig and Antoine JérômeBalard.

The correct answer between allthe choices given is the third choice. I am hoping that this answer hassatisfied your query and it will be able to help you in your endeavor, and ifyou would like, feel free to ask another question.

Answer: Br

Explanation:

As Bromine is short of only 1 electron to attain noble gas configuration, it will release energy as more stable species have less energy. Thus bromine would release most energy while adding an an electron to a neutral atom in the gas phase.

All other species Na, Al and S would not attain stable configuration on addition of electron and hence no energy would be released.

Answer: Therefore, the molar mass of the unknown substance is 68.4 g/mol.

Explanation: We can use the freezing point depression equation to solve for the molar mass of the unknown substance:

ΔT = Kf × m

where ΔT is the change in freezing point, Kf is the freezing point depression constant of the solvent (naphthalene), and m is the molality of the solution.

First, we need to calculate the molality of the solution:

molality = moles of solute / mass of solvent (in kg)

We don't know the number of moles of the unknown substance, but we can assume that the naphthalene does not contribute significantly to the total mass of the solution (since its mass is much smaller than the mass of the unknown substance). Therefore, we can use the entire mass of the solution (1000g + 12.3g = 1012.3g) as the mass of solvent.

mass of solute = 1000g

mass of solvent = 12.3g

mass of solution = 1012.3g

molality = (1000g / molar mass) / (12.3g / 1000g) = 81.3 / molar mass

Next, we need to calculate the change in freezing point:

ΔT = 1.2∘C

Finally, we can use the freezing point depression constant of naphthalene to solve for the molar mass of the unknown substance:

Kf for naphthalene = 6.8∘C/m

ΔT = Kf × m

1.2 = 6.8 × (81.3 / molar mass)

molar mass = 68.4 g/mol

Therefore, the molar mass of the unknown substance is 68.4 g/mol.

Answer:

protons: 36

neutrons:48

electrons:36

Explanation:

the number of protons in an element is = to the atomic # (36)

the number of neutrons is the atomic mass - atomic # (84-36=48)

In a neutral charged element the # of protons = # of electrons

The percentage yield of the reaction has been 46.74%.

Percentage yield can be given as the ratio of the actual yield to the theoretical yield.

For the theoretical yield, the balanced equation will be:

Thus, 2 moles of ZnS will give 2 moles of ZnO.

The moles of 46.5 g ZnS:

Moles =

ZnS =

ZnS = 0.477 mol

The moles of 13.3 grams Oxygen:

Oxygen =

Oxygen = 0.415 mol.

The moles of 18.14 grams ZnO:

ZnO =

ZnO = 0.222 mol

According to the balanced chemical equation,

2 moles ZnO = 2 moles ZnS

0.222 mol ZnO = 0.222 mol ZnS

2 moles ZnO = 3 moles Oxygen

0.222 mol ZnO = 0.334 mol of Oxygen

Since, both the reactants are in enough concentration,

The theoretical yield can be calculated with any of the reactants. The theoretical yield of ZnO from 46.5 grams of ZnS can be given as:

1 mole ZnS = 1 mol ZnO

0.477 mol of ZnS = 0.477 mol of ZnO.

The mass of 0.477 mol of ZnO:

Mass = moles molecular weight

Mass of ZnO = 0.477 81.38

Mass of ZnO = 38.818 grams.

The theoretical yield of ZnO = 38.818 g.

The actualyield of ZnO = 18.14 g.

Percentage yield =

Percentage yield = 46.74 %

The percentage yield of the reaction has been 46.74%.

For more information about the percentage yield, refer to the link:

brainly.com/question/11715808

Answer: you cannot find its new volume by using these known values and Boyle's law because the temperature does not remain constant.

Explanation:

Boyle's law states that the volume of a fixed amount of gas, at a constant temperature, varies inversely with the pressure.

So, it is a condition that the temperature does not change.

For the wheater ballon case, as it travels through the atmosphere, the temperature at different altitudes will be different.

So, you might use other equation of states, such as the combined law, which does deal with changes in the three variables: volume, pressure, and temperature.

The mathematical formulation of Boyle's law is:

pV = constanjt ⇒ p₁ V₁ = p₂ V₂, at constant T.

The mathematical formulation of the combined law of gases is:

pV/T = constant ⇒ p₁ V₁ / T₁ = p₂ V₂ / T₂, for a fixed amount of gas, then it might work for the weather ballon (if you know the initial and end temperatures).

You cannot find the new volume by using initial volume of the weather balloon and air pressure ai its initial and final altitudes and Boyle’s law because the given values are not the same. Boyle’s law holds for the pressure and volume of the GAS at constant temperature. Here you are given the air pressure outside the weather balloon not the inside of the balloon. They have different gases and so it would not apply.