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3 years ago

How many neutrons does element X have if its atomic number is 31 and its mass number is 84?

1 answer:

Alex3 years ago

8 0

Atomic number is protons + electrons
Mass number is protons + neutrons
So to calculate the number of neutrons, you do
atomic number - atomic mass
31 - 84 = - 53

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What is an electrolyte in a battery?

levacccp [35]

The acid in a battery is an electrolyte.

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3 years ago

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In which orbital does an electron in a bromine atom experience the greatest effective nuclear charge?

asambeis [7]

First let us determine the electronic configuration of Bromine (Br). This is written as:

Br = [Ar] 3d10 4s2 4p5

Then we must recall that the greatest effective nuclear charge (also referred to as shielding) greatly increases as distance of the orbital to the nucleus also increases. So therefore the electron in the farthest shell will experience the greatest nuclear charge hence the answer is:

4p orbital

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4 years ago

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Two pipes with 1 meter diameters join to become one pipe with 2 meter diameter. Water was flowing in first pipe at 500 kg/s and

zloy xaker [14]

Answer:

The mass flow rate at the exit of the 2 meter diameter pipe is 1442 kg/s

Explanation:

If the oil is flowing in the 1m diameter pipe at 0.8 m/s, we can calculate the flow as

$Q=\bar{v}*A=\bar{v}*(\pi/4*D^{2} )=0.8m/s*0.785m^{2} =0.628m^{3}/s$

The mass flow is

$M=\rho*Q=1500 kg/m3*0.628m3/s=942kg/s$

The mass flow rate at the exit of the 2 meter diameter pipe is

$M=M_w+M_o=500 kg/s+942kg/s=1442kg/s$

3 0

3 years ago

Ming has two unknown substances. One is nonpolar, and the other is polar.

sweet-ann [11.9K]

Answer:

Test for an odor. The nonpolar substance should have a higher volatility and stronger odor because of its London dispersion forces.

Explanation:

To help Ming identify the non-polar compound, assuming the non-polar compound will have an odor test for it and most importantly, the non-polar substance should have a higher volatility due to its London dispersion forces.

London dispersion forces are weak attractions found between non-polar molecules and noble gases.
They account for the reason why compounds as such are volatile

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3 years ago

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A sulfuric acid solution containing 571.6 g of H2SO4 per liter of solution has a density of 1.329 g/cm3. Calculate (a) the mass

IgorLugansk [536]

Answer:

a) 43%

b) 0.122

c) 7.70 molal

d) 5.83 M

Explanation:

Step 1: Data given

Mass of H2SO4 = 571.6 grams

Density of H2SO4 = 1.329 g/cm³ this means 1.329 grams per 1 mL or 1329 grams per 1L

a) Calculate mass percentage

Mass % = (571.6 grams / 1329 grams)* 100% = 43%

b) Calculate mole fraction

Number of moles H2SO4 = Mass H2SO4 / Molar mass H2SO4

Moles H2SO4 = 571.6 grams / 98.08 g/mol

Moles H2SO4 = 5.83 moles

Moles H2O = (1329 -571.6)/18.02 = 42.03 moles

Total moles = 5.83 + 42.03 = 47.86 moles

Mole fraction H2SO4 = Moles of solute (H2SO4)/ Total moles

Mole fraction H2SO4 = 5.83 moles / 47.86 moles

Mol fraction h2SO4 = 0.122

c) Calculate the molality

Mass of solvent = 1329 grams - 571.6 grams = 757.4 grams = 0.7574 kg

Molality of H2SO4 = number of moles H2SO4 / mass of solvent

Molality H2SO4 = 5.83 moles / 0.7574 kg

Molality H2SO4 = 7.70 molal

d) Calculate Molarity

Molarity H2SO4 = Number of moles H2SO4 / volume

Molarity H2SO4 = 5.83 moles / 1L = 5.83 M

6 0

3 years ago