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4 years ago

Who described the atom as being like plum pudding?

Chemistry

1 answer:

matrenka [14]4 years ago

7 0

Answer:

Explanation:

J.J. Thomson

The plum pudding model is an early 20th century model of an atom. It was later found to be wrong. It was proposed by J.J. Thomson in 1904, after the electron had been discovered, but before the atomic nucleus was discovered.

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What is the volume of a salt crystal measuring 2.44 × 10–2 m by 1.4 × 10–3 m by 8.4 × 10–3 m?

Dima020 [189]

All solids have an orderly internal structure with repeating bonding patterns between atoms, ions, or molecules. They are called crystal lattices. They are a 3-dimensional arrangement of atoms inside a crystal. The volume of this crystal is:

Volume = 2.44 × 10^–2 m x 1.4 × 10^–3 m x 8.4 × 10^–3 m = 2.87 x 10^-7 m^3

6 0

3 years ago

Read 2 more answers

An interaction of systems allows for the body to warm itself when it is cold. Which processes help the body warm up when it is c

Dmitry_Shevchenko [17]

Answer:

shivering

hair on the body standing up

goosebump forming

Explanation:

The processes that help the body warm-up from the available options include the shivering of the body, formation of goosebumps on the skin, and the standing up of hairs on the body.

When the temperature of the body falls below the setpoint or the environment is cold, a homeostatic response is triggered and a signal is sent from the control center to the muscles of the body. The muscles start shaking in order to generate heat to raise the temperature of the body. At the same time, the tiny muscles at the base of the hairs on the skin contract and pull the hairs erect, causing goosebumps in the process.

6 0

3 years ago

Read 2 more answers

A reaction A(aq)+B(aq)↽−−⇀C(aq) has a standard free‑energy change of −4.20 kJ/mol at 25 °C. What are the concentrations of A, B,

Dafna1 [17]

Answer : The concentration of $A,B\text{ and }C$ at equilibrium are 0.132 M, 0.232 M and 0.168 M respectively.

Explanation :

The given chemical reaction is,

$A(aq)+B(aq)\rightleftharpoons C(aq)$

First we have to calculate the equilibrium constant for the reaction.

The relation between the equilibrium constant and standard free‑energy is:

$\Delta G^o=-RT \ln k$

where,

$\Delta G^o$ = standard free‑energy change = -4.20 kJ/mole

R = universal gas constant = 8.314 J/mole.K

k = equilibrium constant = ?

T = temperature = $25^oC=273+25=298K$

Now put all the given values in the above relation, we get:

$-4.20kJ/mole=-(8.314J/mole.K)\times (298K) \ln k$

$k=5.45$

Now we have to calculate the concentrations of A, B, and C at equilibrium.

The given equilibrium reaction is,

$A(aq)+B(aq)\rightleftharpoons C(aq)$

Initially 0.30 0.40 0

At equilibrium (0.30-x) (0.40-x) x

The expression of equilibrium constant will be,

$k=\frac{[C]}{[A][B]}$

$5.45=\frac{x}{(0.30-x)\times (0.40-x)}$

By solving the term x, we get

$x=0.168\text{ and }0.716$

From the values of 'x' we conclude that, x = 0.716 can not more than initial concentration. So, the value of 'x' which is equal to 0.716 is not consider.

The value of x will be, 0.168 M

The concentration of $A$ at equilibrium = (0.30-x) = 0.30 - 0.168 = 0.132 M

The concentration of $B$ at equilibrium = (0.40-x) = 0.40 - 0.168 = 0.232 M

The concentration of $C$ at equilibrium = x = 0.168 M

3 0

4 years ago

There is a type of algae that lives in the cells of corals. These algae process carbon through photosynthesis and pass it on to

Blizzard [7]

Corals will continue to expel algae from their cells if global warming continues, in order to avoid poisonous buildup. Corals will perish as a result of this. The algae are not protected and cannot perform photosynthesis without the presence of corals. The algae will also perish as a result of this.

7 0

3 years ago

A sample of gas occupies 6. 8 L at 327 c what will be it volume at 27 c if the pressure and number of particles do not change

Vitek1552 [10]

A sample of gas occupies 6. 8 L at 327 c and the volume at 27 c if the pressure and number of particles do not change is 3.401 L.

<h3>What is volume?</h3>

Volume is a measurement of the three-dimensional space that is occupied. Numerous imperial units or the SI-derived units, such as the cubic meter and liter, are frequently used to quantify it numerically (such as the gallon, quart, cubic inch). Volume and the length (cubed) have a symbiotic relationship. The volume of a container is typically thought of as its capacity, not as the amount of the space it takes up. In the other words, the volume is the amount of fluid (liquid or gas) that the container may hold.

Volume was initially measured using naturally occurring vessels of a comparable shape and then with standardized containers. Arithmetic formulas can be used to quickly calculate the volume of the several straightforward three-dimensional shapes. If a formula for shape's boundary is known, it is possible to use integral calculus to determine the volumes of more complex shapes. No object in dimensions of zero, one, or two has volume; in the dimensions of four and above, the hypervolume is a concept similar to the standard volume.

In solving the any gas law problems, kelvin temperature will be used.

kelvin = degree celsius + 273.15

Kelvin = 327 + 273.15

= 600.15 K

Kelvin = 27 + 273.15

= 300.15 K

Given Data;

$V_{1}$ (the initial volume) = 6.8 L $V_{2}$ (the final volume) = ? unknown

$T_{1}$ (the initial temperature = 327 °C $T_{2}$ (the final temperature) = 27 °C

=( 600.15 K) = (300.15 K)

This problem can be solve using the Charles' Law which states that volume is directly proportional to kelvin temperature of gases if amount of gas and pressure are constant. If the temperature decreases, volume decreases.

Formula of the Charles' Law is $\frac{V_{1} }{T_{1} }= \frac{V_{2} }{T_{2} }$

To solve for V2, we can used formula $V_{2} =\frac{V_{1}T_{2} }{T_{1} }$

$V_{2} =\frac{V_{1}T_{2} }{T_{1} }$

= 6.8 L × 300.15 K / 600.15 K (cancel the unit kelvin)

= 2041.02 L / 600.15

$V_{2}$ = 3.401 L

Therefore, volume is 3.401 L

To know more about volume visit: brainly.com/question/1578538

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5 0

1 year ago