PLEASE HELP, I'M BEGGING YOU!

Komok [63]

Atomic number and the number of protons are the same...
Neutrons = Mass number - number of protons
Electrons are same # unless there is a charge
The whole number you see on the periodic table is the atomic number of the element which is also same as the number of protons

1) carbon - 14 ; Mass number = 14 , Protons = 6 , Neutrons = 14 - 6 = 8
  Electrons = 6

2) Lead - 208 ; Mass # = 208 , Protons = 82 , Neutrons = 208 - 82 = 126
  Electrons = 82

3) Uranium - 239 ; Mass # = 239  , Protons = 92,Neutrons = 239 - 92 = 147
Electrons =  92

4) Uranium - 238 ; Mass # = 238 , Protons = 92 , Neutrons = 238 - 92 = 146
Electrons = 92

5) Tin - 118 ; Mass # = 118 , Protons = 50 , Neutrons = 118 - 50 = 68
Electrons = 50

8 0

3 years ago

How many liters of a 1.5 M solution can you make if you have .50 mol of KCl?

vaieri [72.5K]

Answer:

The answer to your question is 0.33 liters

Explanation:

Data

Volume = ?

Molarity = 1.5 M

number of moles = 0.5

Formula

$Molarity = \frac{number of moles }{volume}$

Solve for V

$Volume = \frac{number of moles}{molarity}$

Substitution

$Volume = \frac{0.5}{1.5}$

Simplification and result

Volume = 0.33 l

7 0

3 years ago

15.24. Calcium hydroxide, also known as slaked lime, is used in industrial processes in which low concentrations of base are req

Ivahew [28]

The concentration of the hydroxide ions, OH¯ in 250 mL of the solution containing the maximum amount of dissolved calcium hydroxide is 0.01728 M

We'll begin by calculating the number of mole of in 0.16 g of Ca(OH)₂. This can be obtained as follow:

Mass of Ca(OH)₂ = 0.16 g

Molar mass of Ca(OH)₂ = 40 + 2[16 + 1] = 74 g/mol

Mole = mass / molar mass

Mole of Ca(OH)₂ = 0.16 / 74

Next, we shall determine the molarity of the stock solution of Ca(OH)₂.

Mole of Ca(OH)₂ = 0.00216 mole

Volume = 100 mL = 100 / 1000 = 0.1 L

<h3>Molarity of Ca(OH)₂ =? </h3>

Molarity = mole / Volume

Molarity of Ca(OH)₂ = 0.00216 / 0.1

<h3>Molarity of Ca(OH)₂ = 0.0216 M</h3>

Next, we shall determine the molarity of the diluted solution. This can be obtained as follow:

Volume of stock solution (V₁) = 100 mL

Molarity of stock solution (M₁) = 0.0216 M

Volume of diluted solution (V₂) = 250 mL

<h3>Molarity of diluted solution (M₂) =?</h3>

0.0216 × 100 = M₂ × 250

2.16 = M₂ × 250

Divide both side by 250

M₂ = 2.16 / 250

Thus, the molarity of the diluted solution is 0.00864 M

Finally, we shall determine the concentration of the hydroxide ions, OH¯ in the diluted solution. This can be obtained as follow:

Ca(OH)₂(aq) —> Ca²⁺(aq) + 2OH¯(aq)

From the balanced equation above,

1 mole of Ca(OH)₂ contains 2 moles of OH¯

Therefore,

0.00864 M Ca(OH)₂ will contain = 2 × 0.00864 = 0.01728 M OH¯

Thus, the concentration of the hydroxide ions, OH¯ in 250 mL of the solution containing the maximum amount of dissolved calcium hydroxide is 0.01728 M

Learn more: brainly.com/question/11471182

7 0

3 years ago

Water _____.

Sergio039 [100]

Answer: is neither an acid nor a base

Explanation: Water is a universal solvent which means it can dissolve most of the substances in it.

Water has high thermal heat capacity , which means large heat is required to heat the water.

Water is not always pure as it gets contaminated by various pollutants present in the atmosphere such as gases, bacteria and suspended matter.

Water is an amphoteric substance which can act as both acid and base, thus can donate and acept [texH^+[/tex] ions.Thus it is neither an acid nor a base.

$HCl+H_2O\rightarrow H_3O^++Cl^-$

Here water is accepting a proton, thus it acts as base.

$NH_3+H_2O\rightarrow NH_4^++OH^-$

Here water is donating a proton, thus it acts as acid.

4 0

3 years ago

3. longitude is measured in degrees, hours, and seconds. a. true b. false

katen-ka-za [31]

Degrees true hours false seconds false

3 0

3 years ago