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3 years ago

I need help with these 4

Chemistry

1 answer:

storchak [24]3 years ago

5 0

Rift Valley Examples

East African
Rhine Rift Valley (Germany)
Baikal Rift Valley (Russia)

Rift Valley Facts/Characteristics

Bordered by fault zones and separating land masses
A portion of land that drops, forming a valley.
Formed as tectonic plates move.

Fossils - Examples

Bones
Shells
Exoskeletons
Stone imprints of animals.

Non Examples of Fossils

Stones
rocks
Some bones (If they are fossils they will be a lot heavier than other bones.

Hope this helps.

You might be interested in

You would know you were in the troposphere If?

lora16 [44]

It were raining on you

7 0

3 years ago

7. Suppose each of these isotopes emits a beta particle. Give the iso-

Volgvan

In a beta emission, the mass number of the daughter nucleus remains unchanged while the atomic number of the daughter nucleus increases by one unit. The following are isotopes produced when the following undergo beta emission;

1) potassium-42 ------> Ca - 42

2) iodine-131 ------------> Xe - 131

3) iron-52 ---------------> Co - 52

4) sodium-24 -----------> Mg -24

The daughter nucleus formed after beta emission is found one place after its parent in the periodic table.

Regarding the stability of the daughter nuclei, a nucleus is unstable if the neutron-proton ratio is less than 1 or greater than 1.5.

Hence, the following daughter nuclei are stable; Ca - 42, Xe - 131, Mg -24.

Learn more: brainly.com/question/1371390

7 0

3 years ago

When 9.2 g of frozen N2O4 is added to a 0.50 L reaction vessel and the vessel is heated to 400 K and allowed to come to equilibr

Amanda [17]

<u>Answer:</u> The value of $K_c$ for the given reaction is 1.435

<u>Explanation:</u>

To calculate the molarity of solution, we use the equation:

$\text{Molarity of the solution}=\frac{\text{Mass of solute}}{\text{Molar mass of solute}\times \text{Volume of solution (in L)}}$

Given mass of $N_2O_4$ = 9.2 g

Molar mass of $N_2O_4$ = 92 g/mol

Volume of solution = 0.50 L

Putting values in above equation, we get:

$\text{Molarity of solution}=\frac{9.2g}{92g/mol\times 0.50L}\\\\\text{Molarity of solution}=0.20M$

For the given chemical equation:

$N_2O_4(g)\rightleftharpoons 2NO_2(g)$

<u>Initial:</u> 0.20

<u>At eqllm:</u> 0.20-x 2x

We are given:

Equilibrium concentration of $N_2O_4$ = 0.057

Evaluating the value of 'x'

$\Rightarrow (0.20-x)=0.057\\\\\Rightarrow x=0.143$

The expression of $K_c$ for above equation follows:

$K_c=\frac{[NO_2]^2}{[N_2O_4]}$

$[NO_2]_{eq}=2x=(2\times 0.143)=0.286M$

$[N_2O_4]_{eq}=0.057M$

Putting values in above expression, we get:

$K_c=\frac{(0.286)^2}{0.143}\\\\K_c=1.435$

Hence, the value of $K_c$ for the given reaction is 1.435

6 0

3 years ago

How many atoms are in 1.204x10^22 moles of arsenic?

ra1l [238]

Answer:

<h2>0.02 moles </h2>

Explanation:

To find the number of moles in a substance given it's number of entities we use the formula

$n = \frac{N}{L} \\$

where n is the number of moles

N is the number of entities

L is the Avogadro's constant which is

6.02 × 10²³ entities

We have

$n = \frac{1.204 \times {10}^{22} }{6.02 \times {10}^{23} } \\ = 0.02$

We have the final answer as

<h3>0.02 moles</h3>

Hope this helps you

7 0

3 years ago

Is the chemical equation balanced?<br><br> Yes or no

Strike441 [17]

I think it is not so no

6 0

2 years ago

Read 2 more answers