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3 years ago

When electrons are filling energy levels, the lowest energy sublevels are occupied first. This is ____________.

Chemistry

2 answers:

ahrayia [7]3 years ago

5 0

It is called Aufbau Principle

Nimfa-mama [501]3 years ago

4 0

When electrons are filling energy levels, the lowest energy sublevels are occupied first. This is Hund's rule.

Hund's rules state that:

Every orbital in a sublevel has to be singularly occupied before any other orbital is able to be doubly occupied.

All of the electrons in single occupied orbitals have to have the same spin to maximize the total spin.

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What are the two types of collisions? What is the difference between them? Types: a. Types: b. Compare and contrast the two type

mr_godi [17]

Answer:

The two types of collisions are :

Type a)

<u>Elastic collision</u>

Type b)

<u>Inelastic collision</u>

Explanation:

Collision : It is the event when two bodies collide with each other for small period of time.

During collision , the bodies exert force to each other.

Example :

When boxer hits with punches .

When bat hits the ball in cricket match.

So, collision is short duration interaction of two objects. When the objects collides , there is change in their velocity.

All collision follow law of conservation of momentum . Their type is decided by , whether they follow conservation of energy also.

<u>Compare and contrast the two types</u>

a) Elastic collision : Those collision in which no loss or gain of kinetic energy will occur. They follow conservation of kinetic energy. Example : ideal gaseous molecule

b) Inelastic collision : Those collision in which Change in kinetic energy will occur. They do not follow conservation of kinetic energy.Almost all conservation are inelastic.

Here Kinetic energy get converted into other form of energy.

5 0

3 years ago

In a calorimetry experiment, a salt is dissolved in water within an insulating container. The temperature of the solution (surro

Stels [109]

Answer:

Explanation:

heat released by the solution

= 120 x 3.18 x ( 25 - 14 )

= 4197.6 J

= 4.1976 kJ

This is the heat gain by the salt

so enthalpy change = + 4.1976 kJ

because there is increase in enthalpy

It is endothermic process .

7 0

3 years ago

An atom has a diameter of 2.50 Å and the nucleus of that atom has a diameter of 9.00×10−5 Å . Determine the fraction of the volu

chubhunter [2.5K]

Answer:

The fraction of the volume of the atom that is taken up by the nucleus is $4.6656\times 10^{-14}$ .

The density of a proton is $6.278\times 10^{14} g/cm^3$ .

Explanation:

Diameter of the atom ,d = 2.50 Å

Radius of the atom ,r = 0.5 d=0.5 × 2.50 Å = 1.25Å

Volume of the sphere= $\frac{4}{3}\pi r^3$

Volume of atom = V

$V=\frac{4}{3}\pi r^3$ ..[1]

Diameter of the nucleus ,d' = $9.00\times 10^{-5}\AA$

Radius of the nucleus ,r' = 0.5 d'= $0.5\times 9.00\times 10^{-5}\AA=4.5\times 10^{-5}\AA$

Volume of nucleus = V'

$V=\frac{4}{3}\pi r'^3$ ..[2]

Dividing [2] by [1]

$\frac{V'}{V}=\frac{\frac{4}{3}\pi r'^3}{\frac{4}{3}\pi r^3}$

$=\frac{r'^3}{r^3}=\frac{(4.5\times 10^{-5}\AA)^3}{(1.25 \AA)^3}$

$\frac{V'}{V}=4.6656\times 10^{-14}$

The fraction of the volume of the atom that is taken up by the nucleus is $4.6656\times 10^{-14}$ .

Diameter of the proton ,d = $1.72\times 10^{-15} m = 1.72\times 10^{-13} cm$

1 m = 100 cm

Radius of the proton,r = 0.5 d= $0.5\times 1.72\times 10^{-13} cm=8.6\times 10^{-14} cm$

Volume of the sphere= $\frac{4}{3}\pi r^3$

Volume of atom = V

$V=\frac{4}{3}\times 3.14\times (8.6\times 10^{-14} cm)^3=2.664\times 10^{-39}cm^3$

Mass of proton, m = 1.0073 amu = $1.0073\times 1.66054\times 10^{-24} g$

$1 amu = 1.66054\times 10^{-24} g$

Density of the proton : d

$d=\frac{m}{V}=\frac{1.0073\times 1.66054\times 10^{-24} g}{2.664\times 10^{-39}cm^3}=6.278\times 10^{14} g/cm^3$

The density of a proton is $6.278\times 10^{14} g/cm^3$ .

5 0

3 years ago

when a compound containing c h and o is completely combusted in air what reactant besides the hydrocarbon is involved in the rea

Arada [10]

When a compound containing C, H and O is completely combusted in air what reactant besides the hydrocarbon is involved in the reaction is Oxygen.

<h3>What is hydrocarbon?</h3>

A hydrocarbon is an organic molecule composed completely of hydrogen and carbon in organic chemistry. Group 14 hydrides include hydrocarbons. Hydrocarbons are often colourless and hydrophobic, with scents that are weak or exemplified by gasoline and lighter fluid. They exist in a wide range of molecular forms and phases, including gases (like methane and propane), liquids (like hexane and benzene), low melting solids (like paraffin wax and naphthalene), and polymers (such as polyethylene and polystyrene). Hydrocarbon refers to naturally occurring petroleum, natural gas, and coal, as well as their hydrocarbon derivatives and refined forms, in the fossil fuel industry. The primary source of energy on the planet is the combustion of hydrocarbons.

To learn more about hydrocarbons visit:

brainly.com/question/17578846

#SPJ4

7 0

1 year ago

Calculate the frequency in hertz of electromagnetic radiation that has a wavelength of 645.0 nm. (c = 3.00 X 10⁸ m/s)

bazaltina [42]

Answer:

1/wavelength

c=1/alpha

6 0

3 years ago