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3 years ago

What is an isotope ? how is the mass calculated ?

Chemistry

1 answer:

leonid [27]3 years ago

8 0

Answer:

Isotopes are variants of a particular chemical element which differ in neutron number, and consequently in nucleon number. All isotopes of a given element have the same number of protons but different numbers of neutrons in each atom

Explanation:

For any given isotope, the sum of the numbers of protons and neutrons in the nucleus is called the mass number. This is because each proton and each neutron weigh one atomic mass unit (amu). By adding together the number of protons and neutrons and multiplying by 1 amu, you can calculate the mass of the atom

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HELP PLEASE ILL GIVE REWARD!!!!!!!!!!!!!!!!

laila [671]

All the information is answered/given in the paragraph except that the study doesn’t show cells in their natural habitat!

7 0

2 years ago

When 150. g zinc sulfide are burned in excess oxygen, 68.5 g of zinc oxide are actually produced, along with sulfur dioxide. Det

Bumek [7]

%yield = 54.6%

<h3>Further explanation</h3>

Percent yield is the compare of the amount of product obtained from a reaction with the amount you calculated

(theoretical)

General formula:

Percent yield = (Actual yield / theoretical yield )x 100%

<h3 />

Reaction

2ZnS+3O₂ ⇒ 2ZnO+2SO₂

MW ZnS = 97.474 g/mol

mol ZnS

$\tt \dfrac{150}{97.474}=1.54$

MW ZnO = 81.38 g/mol

mol ZnO (from mol ZnS as limiting reactant, O₂ excess)

$\tt \dfrac{2}{2}\times 1.54=1.54$

Actual ZnO produced

$\tt 1.54\times 81.38=125.33~g$

Theoretical production = 125.388

%yield

$\tt \dfrac{68.5}{125.33}\times 100\%=\boxed{\bold{54.6\%}}$

4 0

2 years ago

a gas occupies 600.0 ml at 20.00 degrees C and 70.00kPa what will be the pressure at 40.00 degrees C and 150.0mL?

Zina [86]

Answer:

P₂ = 299.11 KPa

Explanation:

Given data:

Initial volume = 600 mL

Initial pressure = 70.00 KPa

Initial temperature = 20 °C (20 +273 = 293 K)

Final temperature = 40°C (40+273 = 313 K)

Final volume = 150.0 mL

Final pressure = ?

Formula:

P₁V₁/T₁ = P₂V₂/T₂

P₁ = Initial pressure

V₁ = Initial volume

T₁ = Initial temperature

P₂ = Final pressure

V₂ = Final volume

T₂ = Final temperature

Solution:

P₂ = P₁V₁ T₂/ T₁ V₂

P₂ = 70 KPa × 600 mL × 313 K / 293K ×150 mL

P₂ = 13146000 KPa .mL. K /43950 K.mL

P₂ = 299.11 KPa

4 0

2 years ago

You have 363 mL of a 1.25M potassium chloride solution, but you need to make a 0.50M potassium chloride solution. How many milli

maxonik [38]

Answer:- 544.5 mL of water need to be added.

Solution:- It is a dilution problem. The equation used for solving this type of problems is:

$M_1V_1=M_2V_2$

where, $M_1$ is initial molarity and $M_2$ is the molarity after dilution. Similarly, $V_1$ is the volume before dilution and $V_2$ is the volume after dilution.

Let's plug in the values in the equation:

$1.25M(363mL)=0.50M(V_2)$

$V_2=\frac{1.25M(363mL)}{0.50M}$

$V_2=907.5mL$

Volume of water added = 907.5mL - 363mL = 544.5 mL

So, 544.5 mL of water are need to be added to the original solution for dilution.

3 0

2 years ago

Identify which trends in the diagrams below describe atomic radius, ionization energy, electron affinity, and electronegativity.

mihalych1998 [28]

a) figure describe ionization energy , electron affinity & electron negativity

b) figure describe Atomic Radius

c) does represent anything

Electronegativity : An atom attracted the bond pair of electrons in a covalent bond is called electronegativity of an element. H-->Cl

Ionization energy : The amount of energy is required to remove of an electron from an isolated gas atom is called Ionization energy. M + IP-----> M+ + e-

Electron affinity: The amount of enery is released when an electron added to an isolated atom is called electron affinity.

X + e- ------> X- =- EA

Atomic radius ; The distance between the center of neuclies and outer most shell is called atomic radius.

8 0

3 years ago