"which of the following statements about electrons is not true?
a) electrons orbit the nucleus rather like planets orbiting the sun.
b) within an atom, an electron can have only particular energies.
c) electrons can jump between energy levels in an atom only if they receive or give up an amount of energy equal to the difference in energy between the energy levels.
d) an electron has a negative electrical charge.
e) electrons have very little mass compared to protons or neutrons

B) Within an atom, an electron can have only particular energies.

Explanation:

As we know that electrons have energy but apart from electrons we know that protons and neutrons inside the nucleus of atom will also have energy in them.

rest all the statements are true as we have

A) Electrons orbit the nucleus rather like planets orbiting the Sun.

TRUE, because electrons can move in stationary orbit around the nucleus

C) Electrons can jump between energy levels in an atom only if they receive or give up an amount of energy equal to the difference in energy between the energy levels.

Difference amount of energy is lost or absorbed by the electron in form of photons

D) An electron has a negative electrical charge.

Charge of an electron is given as

E) Electrons have very little mass compared to protons or neutrons

Mass of an electron is given as

mass of proton or neutron

  the grams     of oxygen gas   that can be produced     is 20.6   grams of o₂

calculation

2liclo₃ →   2 licl + 3 o₂

step 1:   find the moles of liclo₃

moles = mass÷ molar mass

from periodic table the molar mass of liclo₃ =6.9 +35.5   +(16 x3) =90.4 g/mol

moles=38.7 g÷90.4 g/mol=0.4281   moles

step 2:   use the   mole ratio   to calculate the moles of o2

from equation above, liclo₃: o₂   is 2: 3  

therefore the moles of   o₂=0.4281 moles x3/2 =0.6422   moles

step 3: find mass   of o₂

mass= moles x molar mass

from periodic table the   molar mass of   o₂ = 16 x2= 32 g/mol

mass=0.6422   moles   x   32 g/mol = 20.6 grams of o₂