Cobalt (Co) has an atomic mass of 59 and an atomic number of 27. Which statement correctly describes an atom of cobalt? O A. An atom of cobalt contains more neutrons than protons.
B. An atom of cobalt contains more electrons than protons.
O C. An atom of cobalt contains the same number of neutrons and protons.
O D. An atom of cobalt contains the same number of neutrons, electrons and protons.

Option A. An atom of cobalt contains more neutrons than protons.

Explanation:

From the question given above, the following data were obtained:

Mass number = 59

Atomic number = 27

Next, we shall determine the number of protons in the atom. This is illustrated below:

Atomic number of an element is simply defined as the number of protons in the atom of the element. Thus,

Atomic number = proton number

Atomic number = 27

Therefore,

Proton number = 27

Next, we shall determine the neutron number. This can be obtained as follow:

Mass number = 59

Proton number = 27

Neutron number =?

Mass number = Proton + Neutron

59 = 27 + Neutron

Collect like terms

Neutron = 59 – 27

Neutron number = 32

Next, we shall determine the number of electrons. This can be obtained as follow:

Since the atom is neutral i.e it has no charge, then, the number of protons and electrons are equal. Thus,

Electron number = Proton number

Proton number = 27

Therefore,

Electron number = 27

Summary:

Mass number = 59

Atomic number = 27

Proton number = 27

Neutron number = 32

Electron number = 27

From the above, we can see that the atom of cobalt contains:

1. More neutrons than protons.

2. The same number of protons and electrons.

Therefore, option A gives the correct answer to the question.

are there answer choices to this question? this seems like a question where you have options to choose from.

  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