All categories

3 years ago

Identify which of the following statements about the isotopes of an element is correct.

Chemistry

1 answer:

kozerog [31]3 years ago

3 0

Answer:

Explanation:

because B is wrong as it doesn't have the same mass number. C is wrong as it has different number of neutrons. D is wrong as it has more neutrons than protons.

You might be interested in

For the decomposition of calcium carbonate, consider the following thermodynamic data (Due to variations in thermodynamic values

In-s [12.5K]

Answer : The temperature in kelvins is, $T>1108.695K$

Explanation : Given,

$\Delta H$ = 178.5 KJ/mole = 178500 J/mole

$\Delta S$ = 161.0 J/mole.K

Gibbs–Helmholtz equation is :

$\Delta G=\Delta H-T\Delta S$

As per question the reaction is spontaneous that means the value of $\Delta G$ is negative or we can say that the value of $\Delta G$ is less than zero.

$\Delta$

The above expression will be:

$0>\Delta H-T\Delta S$

$T\Delta S>\Delta H$

$T>\frac{\Delta H}{\Delta S}$

Now put all the given values in this expression, we get :

$T>\frac{178500J/mole}{161.0J/mole.K}$

$T>1108.695K$

Therefore, the temperature in kelvins is, $T>1108.695K$

7 0

3 years ago

What is the trend in electronegativity for elements on the periodic table? It decreases across a period and increases down a gro

lilavasa [31]

It increases across a period and decreases down a group. A good way to remember this is that fluorine is the most electronegative atom, and it's to the top right of the table.

6 0

4 years ago

Read 2 more answers

What does the absolute magnitude of a star depend on?

Serggg [28]

C. Distance from Earth

The observed brightness of a star (the apparent magnitude) to an absolute magnitude, you need to know the distance [d], to the star. Alternatively, if we know the distance and the apparent magnitude [m] of a star, we can calculate its absolute magnitude [d].

*paraphrased from "COSMOS.com"

8 0

4 years ago

Learn how changes in binding free energy affect binding and the ratio of unbound and bound molecules.

Delvig [45]

C)[D]/[ED] = 5.20

D)[D]/[ED] = 5.20

E)[D']_T = 1.495* 10 ^-7 M

F)[D'] / [ED'] = 0.0579

Explanation:

E = 250 nM =2.5* 10 ^-7 mol/L , T=298.15 K

Dissociation constant of K_D = 1.3 μM (1.3 *10 ^-6 M)

E + D ⇄ ED → K_a = [ED] / [D][E] (association constant)

ED ⇄ E + D → K_D = [E][D] / [ED] (dissociation constant)

[E] =2.5*10^-7 mol/L

K_D = 1.3* 10^-6 M

K_D = [E][D] / [ED] → [D]/[ED] = K_D / [E]

= [D]/[ED] = 1.3* 10 ^-6 / 2.5 *10^-7

= 13/25 * 10

=130/25 = 5.20

[D]/[ED] = 5.20

ΔG =RTln Kd

ΔG_2 for E and D = 1.987 * 298.15 * ln 1.3*10^-6

ΔG_2 592.454 * [ln 1.3 +ln 10^-6]

ΔG_1 = 592.424 [0.2623 - 13.8155]

ΔG_2 = -592.424 * 13.553

ΔG_1 = -8184.633 cal/ mol

ΔG_1 = -8184.633 * 4.18 J/mol = -34244.508 J?mol

ΔG_1 = -34.245 KL/mol

so, ΔG_2 = ΔG_1 - 10.5 KJ/mol

ΔG_2 = -34.245 - 10.5

ΔG_2 = -44.745KJ / mol

ΔG_2 =RT ln K_D

-44.745 *10^3

=8.314 *298.15 lnK_D

lnK_D' = - 44745 / 2478.81 g

ln K_D' = -18.051

K_D' = -18.051

K_D' = e^-18.051

[D]/[ED] = 5.20

[E] = 2.5* 10 ^-7 mol/ L = a

K_D' = [E][D] / [ED'] E +D' → ED'

K_D' = a/2(x-(a/2) / (a/2)

KD' = x - a/2

=2.447 *10^-8 = (2.5/2) * 10^-7

x=2.447 * 10^-8 + 1.25 * 10^-7

x = 2.447 *10^-8 + 1.25 * 10 ^-7

x= 10^-7 [1.25 + 0.2447]

x = 1.4947 * 10^-7

[D']_T = 1.495* 10 ^-7 M

K_D' = [E][D'] / [ED']

[D'] / [ED'] = KD' / [E]

[D'] / [ED'] = 1.447 *10^-8 / 2.5* 10^-7

[D'] / [ED'] = 0.5788 * 10^-1

[D'] / [ED'] = 0.0579

5 0

3 years ago

Earth receives some of the Sun's energy in the form of heat and light.

Deffense [45]

Answer:

The sun generates energy from a process called nuclear fusion. During nuclear fusion, the high pressure and temperature in the sun's core cause nuclei to separate from their electrons. Hydrogen nuclei fuse to form one helium atom. During the fusion process, radiant energy is released.

Explanation:

6 0

3 years ago

Read 2 more answers