All categories

2 years ago

How does the electron arrangement change moving vertically down a group?

Chemistry

1 answer:

vampirchik [111]2 years ago

6 0

Answer:

Electrons arrangement change is almost constant down the group, hence nuclear charge is almost constant.

But the energy levels on which electrons are arranged increase down the group, hence shielding or screening effect increases.

You might be interested in

Looking at the different chemical structures, which one(s) might be able to hold

Romashka-Z-Leto [24]

Answer:

c) Fullerene and carbon nanotubes because they have empty spaces inside the molecules

Explanation:

Fullerene and carbon nanotubes would be the most desired in order to hold the cancer fighting drugs and to carry them through the body safely.

These molecules have empty spaces in them.
The cavities makes it possible for storage.
As they pass through the body, they can be held perfectly well to their target site of action.

3 0

2 years ago

Many power plants produce energy by burning carbon-based fuels, which also produces carbon dioxide. Carbon dioxide is a greenhou

RUDIKE [14]

Answer:

a) 2.541 mol/MJ;

b) 1.124 mol/MJ;

c) 0.4354 mol/MJ;

d) 0.1835 mol/MJ

Explanation:

The enthalpy of formation (ΔH°f) is the enthalpy of a reaction to form a compound by its constituents. For CO₂, ΔH°f = - 393.5 kJ/mol.

The enthalpy of a reaction is the sum of the enthalpy of the products (each one multiplied by the number of moles) less the sum of the enthalpy of the reactants (each one multiplied by the number of moles). The ΔH°f for simple substances (with one atom) is 0. The combustion is the reaction between the fuel and the oxygen.

a) The combution reaction is:

C(s) + O₂(g) → CO₂(g)

ΔH°rxn = -393.5 kJ/mol = -393.5x10⁻³ MJ/mol

Number of moles per MJ released: 1/|ΔH°rxn|

n = 1/(393.5x10⁻³) = 2.541 mol/MJ

b) The combustion reaction is:

CH₄(g) + 2O₂(g) → CO₂(g) + 2H₂O(l)

H₂O is in the liquid state because it's at 1 atm and 25ºC.

ΔH°f, H₂O(l) = -285.3 kJ/mol

ΔH°f, O₂(g) = 0

ΔH°f, CH₄(g) = -74.8 kJ/mol

ΔH°rxn = [2*(-285.3 ) + 1*(-393.5)] - [1*(-74.8)]

ΔH°rxn = -889.3 kJ/mol = -889.3x10⁻³ MJ/mol

n = 1/889.3x10⁻³ = 1.124 mol/MJ

c) C₃H₈(g) + 10O₂(g) → 3CO₂(g) + 4H₂O(l)

ΔH°f,C₃H₈(g) = -25.2 kJ/mol

ΔH°rxn = [4*(-285.3) + 3*(-393.5)] - [1*(-25.2)]

ΔH°rxn = -2,296.5 kJ/mol = -2.2965 MJ/mol

n = 1/2.2965 = 0.4354 mol/MJ

d) C₈H₁₈(l) + (25/2)O₂(g) → 8CO₂(g) + 9H₂O(l)

ΔH°f, C₈H₁₈(l) = -250.1 kJ/mol

ΔH°rxn = [9*(-283.5) + 8*(-393.5)] - [1*(-250.1)]

ΔH°rxn = -5,449.4 kJ/mol = -5.4494 MJ/mol

n = 1/5.4494 = 0.1835 mol/MJ

4 0

2 years ago

A 2.04 g lead weight, initially at 10.8 oC, is submerged in 7.62 g of water at 52.3 oC in an insulated container. clear = 0.128

alisha [4.7K]

Answer: The final temperature of both the weight and the water at thermal equilibrium is $50.26^{o}C$ .

Explanation:

The given data is as follows.

mass = 7.62 g, $T_{2} = 10.8^{o}C$

Let us assume that T be the final temperature. Therefore, heat lost by water is calculated as follows.

q = $mC \times \Delta T$

= $7.62 g \times 4.184 J/^{o}C \times (52.3 - T)$

Now, heat gained by lead will be calculated as follows.

q = $mC \times \text{Temperature change of lead}$

= $2.04 \times 0.128 \times (T - 11.0)$

According to the given situation,

Heat lost = Heat gained

$7.62 g \times 4.184 J/^{o}C \times (52.3 - T)$ = $2.04 \times 0.128 \times (T - 11.0)$

T = $50.26^{o}C$

Thus, we can conclude that the final temperature of both the weight and the water at thermal equilibrium is $50.26^{o}C$ .

7 0

3 years ago

Western regions Facts

babunello [35]

This region has both the state with the smallest population (Wyoming) and the largest population (California).
Alaska's land area is much bigger than any other state, but it has one of the lowest populations.
The western US takes up about half of the land of the United States.

The western United States is the region comprising the westernmost states of the United States. As American settlement in the U.S. expanded westward, the meaning of the term the West changed. Before about 1800, the crest of the Appalachian Mountains was seen as the western frontier.

Hope this helps :)

Have a great day!

7 0

2 years ago

How are muscles able to keep making energy even when no food is eaten and glucose levels are low?

erastova [34]

Although lipids hold the majority of the body's energy reserves, glycogen is the body's primary energy source.

Glucose is a polymer that makes up glycogen. Our body's primary source of energy is carbs. The remaining glucose in the body is turned into glycogen and stored in various places, but the majority of our body's energy reserves are found in fats, which are kept in the form of lipids.

Where does the energy come from in the muscles?

The chemical energy that is stored in our meals is used by muscles to produce heat and motion energy (kinetic energy). Energy is necessary for maintaining body temperature, promoting physical activity, and enabling tissue growth and repair. Foods high in protein, fat, and carbohydrates provide energy.

What Takes Place to Muscles in the Absence of Glucose?

Your body converts carbs, such as those found in bread or fruit, into glucose after consumption. Glycogen is the form of glucose that is stored in your muscles and liver and is used for energy when you are not eating or while you are exercising.

To learn more about source of energy in body, visit

brainly.com/question/7493628

#SPJ13

7 0

9 months ago

How does the electron arrangement change moving vertically down a group?​

How does the electron arrangement change moving vertically down a group?