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3 years ago

Which property is true for metals

Chemistry

2 answers:

san4es73 [151]3 years ago

6 0

most metals conduct electricity and are very dull to the look. most metals are toxic if eaten and are hard.

aluminum is a type of metal they is softer than the opther and conducts eletricty like a boss.

nickel on the opther hand is also a metal but does not conduct a lot of electricy.

metals can be bent and others can break,

baherus [9]3 years ago

5 0

Metals are solid, shiny, and good conductors of electricity and heat
hope this helps :)

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How could an alpha particle pass straight through the metal foil and strike the center of the phosphor screen on the other side

EleoNora [17]

It was due to the metal foil in which the alpha particles can't even pass through. This experiment conducted by Rutherford led to the discovery of protons.

4 0

3 years ago

An aqueous KNO3 solution is made using 72.5 g of KNO3 diluted to a total solution volume of 2.00 L. Calculate the molarity, mola

Sonja [21]

Answer:

The molarity is 0.359 $\frac{moles}{L}$

The molality is 0.354 $\frac{moles}{kg}$

The mass percent of the solution es 3.45%

Explanation:

Molarity is a unit of concentration that indicates the amount of moles of solute that appear dissolved in each liter of the mixture. It is determined by:

$Molarity (M)=\frac{number of moles of solute}{volume}$

Being:

K: 39 g/mole
N: 14 g/mole
O: 16 g/mole

The molar mass of KNO₃ is:

KNO₃= 39 g/mole + 14 g/mole + 3*16 g/mole= 101 g/mole

You can apply the following rule of three: if 101 grams of KNO₃ are present in 1 mole, 72.5 grams in how many moles are present?

$moles of KNO_{3}=\frac{72.5 grams*1 mole}{101 grams}$

moles of KNO₃= 0.718

So you have:

moles of KNO₃= 0.718
volume= 2 L

Applying this quantity in the definition of molarity:

$molarity=\frac{0.718 moles}{2 L}$

Molarity= 0.359 $\frac{moles}{L}$

The molarity is 0.359 $\frac{moles}{L}$

Molality is a way of measuring the concentration of solute in solvent and indicates the amount of moles of solute in each kilogram of solvent.

Then the molality is calculated by:

$Molality=\frac{moles of solute}{mass of solvent in kilograms}$

Density is defined as the property that matter, whether solid, liquid or gas, has to compress in a given space. That is, it is the amount of mass per unit volume. So, if the density of 1.05 g / mL for the solution indicates that in 1 mL of solution there are 1.05 grams of solution, in 2000 mL (where 2L = 2000 mL, because 1 L = 1000mL) how much mass is there?

$mass=\frac{2000 mL*1.05 grams}{1 mL}$

mass= 2100 grams

Since mass solution = mass water + mass KNO₃

then mass water = mass solution - mass KNO₃

Being mass solution 2100 grams and mass KNO₃ 72.5 grams, and replacing you get: mass water= 2100 grams - 72.5 grams

mass water= 2,027.5 grams

Then, being:

moles of KNO₃= 0.718
mass of solvent in kilograms= 2.0275 kg (being 2,027.5 grams= 2.0275 kilograms because 1,000 grams= 1 kilogram)

Replacing in the definition of molality:

$molality=\frac{0.718 moles}{2.0275 kg}$

molality= 0.354 $\frac{moles}{kg}$

The molality is 0.354 $\frac{moles}{kg}$

The mass percent of a solution is the number of grams of solute per 100 grams of solution. Then the mass percent is the mass of the element or solute divided by the mass of the compound or solute and the result of which is multiplied by 100 to give a percentage.

$mass percent=\frac{mass of solute}{mass of solution} *100$

So, in this case:

$mass percent=\frac{72.5 grams}{2100 grams} *100$

mass percent= 3.45 % KNO₃ by mass

The mass percent of the solution es 3.45%

3 0

2 years ago

The period of a sound 440-Hertz sound wave is how many second/second.

masha68 [24]

440 hertz = 440/seconds
1/440 seconds = period of the sound wave.
so Answer is 2.2727272* 10^-3 second or 1/440 seconds

3 0

3 years ago

C2H4+

klasskru [66]

Answer:

A. Theoretical yield = 3.51g

B. %yield = 75%

Explanation:

The balanced equation for the reaction is given below:

C2H4 + 3O2 —> 2CO2 + 2H2O

Molar Mass of O2 = 16 x 2 = 32g/mol

Mass of O2 from the balanced equation = 3 x 32 = 96

Molar Mass of H20 = (2x1) + 16 = 18g/mol

Mass of H2O from the balanced equation = 2 x 18 = 36g

A. From the equation,

96g of O2 produced 36g of H2O

Therefore, 9.35g of O2 will produce = (9.35 x 36)/96 = 3.51g of H2O

Therefore,theoretical yield of water (H2O) = 3.51g

B. Theoretical yield = 3.51

Actual yield = 2.63g

%yield =?

%yield = Actual yield/Theoretical yield x 100

%yield = 2.63/3.51

%yield = 75%

4 0

3 years ago

6) When a substance such as ice melts, its temperature increases. Describe what happens to the arrangement of the water molecule

Vinvika [58]

When temperature increases, there is more energy in a substance. For example, when water boils, more energy is produced. The arrangement of molecules in a solid are closer together and more packed, while the arrangement of molecules in a liquid are father apart and less packed.

4 0

3 years ago