Which of the following descriptions of gravitational force is NOT TRUE?

Why are bottles made from amorphous solid's such as plastic and glass

notsponge [240]

They will mold into different shapes

7 0

3 years ago

In what situations are van der waals forces the most significant

viktelen [127]

Its most significant when all other forces are absent

7 0

3 years ago

A mixture of carbon dioxide and helium gases is maintained in a 7.91 L flask at a pressure of 1.42 atm and a temperature of 33 °

Crank

Answer:

The gas mixture contains 1.038 grams of helium

Explanation:

Step 1: Data given

Volume of the flask = 7.91 L

Total Pressure = 1.42 atm

Temperature = 33 °C

Mass of CO2 = 8.25 grams

Molar mass of CO2 = 44.01 g/mol

Molar mass of He = 4 g/mol

Step 2: Calculate total number moles of gas

p*V = n*R*T

⇒ p = the pressure = 1.42 atm

⇒ V = the volume = 7.91 L

⇒ n= the number of moles = TO BE DETERMINED

⇒ R = the gas constant = 0.08206 L* atm/K*mol

⇒ T = the temperature = 33 °C = 306 Kelvin

n = (p*V)/(R*T)

n = (1.42*7.91)/(0.08206 * 306)

n = 0.447 moles

Step 3: Calculate moles of CO2

Moles CO2 = mass CO2 / Molar mass CO2

Moles CO2 = 8.25 grams / 44.01 g/mol

Moles CO2 = 0.1875 moles

Step 4: Calculate moles of Helium

Moles Helium = total moles of gas - moles of CO2

Moles Helium = 0.447 - 0.1875 = 0.2595 moles of helium

Step 5: Calculate mass of helium

Mass of helium = moles of helium * molar mass of helium

Mass of helium = 0.2595 moles * 4 g/mol

Mass of helium = 1.038 grams

The gas mixture contains 1.038 grams of helium

8 0

3 years ago

The element carbon exists in several different forms. Pure carbon can be found in the form of diamonds, coal, and the graphite i

UNO [17]

Answer:

B) All carbon atoms have 6 neutrons.

Explanation:

The false statement from the given choices is that all carbon atoms have 6 neutrons.

There is a phenomenon called isotopy in chemistry.

Isotopy is the existence of two or more atoms of the same element having the same atomic number but different mass numbers due to the differences in the number of neutrons in their various nuclei.

These atoms of elements are called isotopes.
Carbon atoms generally have proton number of 6 which is the same as the atomic number.
As with all atoms, the mass number or atomic mass equals the number of protons and neutrons.

For the isotopes of carbon, their number of neutrons differs.

For example:

¹²₆C ¹³₆C ¹⁴₆C

The number of neutrons differs in the above isotopes.

Number of neutrons = mass number - atomic number;

¹²₆C , number of neutrons = 12 - 6 = 6

¹³₆C, number of neutrons = 13 - 6 = 7

¹⁴₆C, number of neutrons = 14 - 6 = 8

Therefore, based on the concept of isotopy, all carbon atoms do not have 6 neutrons.

7 0

3 years ago

Increasing temperature makes a

LenKa [72]

Answer:

High temperature increases the number of high energy collisions

Explanation:

Increasing the temperature a reaction takes place at increases the rate of reaction. At higher temperatures, particles can collide more often and with more energy, which makes the reaction take place more quickly.

5 0

3 years ago