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3 years ago

Use the periodic table to answer the questions below.

Chemistry

2 answers:

Yanka [14]3 years ago

7 0

Answer:

where is the diagram shown

ExtremeBDS [4]3 years ago

4 0

Answer: 1s2, 2s2, 2p3

Explanation: Nitrogen is an element number 7 on the periodic table which means that it has 7 proton. And for an atom to maintain its electrical neutrality, the number of proton is equal to the number of electron. That is, equal number of positively and negatively charge.

So, 7 electrons of Nitrogen is

1s2, 2s2, 2p4

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Nault 25000L 250 our = 25000L 15040 8. How many grams of CaCl2 are needed to make 150.0 mL of a 0.500 M CF solution? (Note: CaCl

yuradex [85]

Answer:

You need 8,324 g of CaCl₂ yo make this solution

Explanation:

Molarity is a way to express concentration in a solution, in units of moles of solute per liter of solution.

To know the grams of CaCl₂ it is necessary to know, first, the moles of this substance with the desired volume and concentration , thus:

0,1500 L × $\frac{0,500 mol}{L}$ = 0,075 CaCl₂ moles

Now, with the molar mass of CaCl₂ you will obtain the necessary grams, thus:

0,075 CaCl₂ moles × $\frac{110,98 g}{mol}$ = 8,324 g of CaCl₂

So, you need 8,324 g of CaCl₂ to make 150,0 mL of a 0,500M solution

I hope it helps!

3 0

3 years ago

How many protons, neutrons, and electrons could an isotope of this atom contain?

Dmitry_Shevchenko [17]

Answer:

The atomic number on the Periodic Table identifies the number of protons in any atom of that element. Copper, atomic number 29, has 29 protons. Finding the atomic number of an element reveals the number of protons.

To find the number of neutrons in the atom, subtract the atomic number from the atomic mass.

8 0

3 years ago

What is refraction? * Bending of light Reflection of light

sdas [7]

Refraction is the bending of light (it also happens with sound, water and other waves) as it passes from one transparent substance into another. This bending by refraction makes it possible for us to have lenses, magnifying glasses, prisms and rainbows. Even our eyes depend upon this bending of light. Hope this helps!

6 0

3 years ago

Read 2 more answers

Calculate the final Celsius temperature when 634 L at 21 °C is compressed to 307 L.

Illusion [34]

Answer:

- 130.64°C.

Explanation:

We can use the general law of ideal gas: PV = nRT.

where, P is the pressure of the gas in atm.

V is the volume of the gas in L.

n is the no. of moles of the gas in mol.

R is the general gas constant,

T is the temperature of the gas in K.

If n and P are constant, and have two different values of V and T:

V₁T₂ = V₂T₁

V₁ = 634.0 L, T₁ = 21.0°C + 273 = 294.0 K.

V₂ = 307.0 L, T₂ = ??? K.

∴ T₂ = V₂T₁/V₁ = (307.0 L)(294.0 K)/(634.0 L) = 142.36 K.

∴ T₂(°C) = 142.36 K - 273 = - 130.64°C.

5 0

3 years ago

Mixture of 120 grams of KClO3 and 300 grams of water until all of the KClO3 has dissolved. At what temperature does this occur?

lozanna [386]

240°C is required to dissolve 120 grams of KClO₃ in 300 g of water.

Explanation:

As per the solubility curve graph of different salts dissolved in 100 g of water, it can be noted that the KClO₃ gets saturated at 100 °C with the solubility of 59 g in it. But here the water is taken as 300 g and the salt is taken as 120 g. The graph shows the solubility of grams of salt in 100 g of water.

So, then we have to find what is the gram of salt present in 100 g of water for the present sample.

300 g of water contains 120 grams of salt.

Then, 1 g of water will contain $\frac{120}{300}$ g of salt.

Then, 100 g of water will contain $\frac{120}{300}*100$ of salt. This means, 100 g of water will contain 40 g of salt in it.

Then, if we check the graph, the corresponding x-axis point on the curve for the y-axis value of 40 g will give us the temperature required to dissolve the salt in water. So 80°C will be required to dissolve 40 g of salt in 100 g of water.

Then, in order to get the temperature required to dissolve 120 g in 300 g of water, multiply the temperature by 3, which will give the result as 80×3=240 °C.

So, 240°C is required to dissolve 120 grams of KClO₃ in 300 g of water.

8 0

3 years ago