Question

scenario 1: medical isotopes (carbon - 14)
doctors use carbon - 14 to track glucose in the body.

1. fill in the chart:

hint:
protons = atomic number
protons = electrons
neutrons = mass number (whole number) - atomic number (protons)

isotope	protons	neutrons	electrons
carbon - 13
carbon - 14

1. why is carbon - 14 still carbon even though it has extra neutrons?

carbon - 14 is still carbon because

1. the periodic table says the atomic mass of carbon is 12.01 amu.

what does this tell us about which isotope (carbon - 12 or carbon - 14) is more common? circle the correct option. carbon - 12 or carbon - 14.
scenario 2: oxygen and climate studies
scientists study oxygen isotopes in ice cores.

1. complete the chart:

isotope	protons	neutrons	neutrons
o - 17
o - 18

1. if oxygens average atomic mass is 15.999 amu, which isotope must be most abundant?

the isotope most common in nature is because

1. why do scientists prefer isotopes instead of just measuring \oxygen atoms\ in climate studies?

complete the following on your own.

isotope	protons	neutrons	electrons
mg - 25
mg - 26

1. which element do these isotopes belong to?

the element is

1. the mass of the element is 24.4 amu. which isotope is the most abundant?

the most abundant isotope for this element is because

Explanation:

Step1: Recall atomic number facts

Carbon has an atomic number of 6. So for all carbon isotopes, the number of protons = 6 and in neutral atoms, number of electrons = number of protons = 6.
For Carbon - 12: Neutrons = 12 - 6=6.
For Carbon - 13: Neutrons = 13 - 6 = 7.
For Carbon - 14: Neutrons = 14 - 6 = 8.

Isotope	Protons	Neutrons	Electrons
Carbon - 13	6	7	6
Carbon - 14	6	8	6

Step2: Explain why Carbon - 14 is carbon

The identity of an element is determined by the number of protons. Carbon - 14 has 6 protons, which is the atomic number of carbon. So it is still carbon even with extra neutrons.
Carbon - 14 is still carbon because it has 6 protons, which defines the element carbon.

Step3: Determine common carbon isotope

The average atomic mass of carbon is 12.01 amu which is very close to 12 amu (the mass of Carbon - 12). So Carbon - 12 is more common.
Carbon - 12

Step4: Recall oxygen atomic number

Oxygen has an atomic number of 8. So for all oxygen isotopes, the number of protons = 8 and in neutral atoms, number of electrons = number of protons = 8.
For O - 16: Neutrons = 16 - 8 = 8.
For O - 17: Neutrons = 17 - 8 = 9.
For O - 18: Neutrons = 18 - 8 = 10.

Isotope	Protons	Neutrons	Electrons
O - 17	8	9	8
O - 18	8	10	8

Step5: Determine common oxygen isotope

The average atomic mass of oxygen is 15.999 amu which is very close to 16 amu (the mass of O - 16). So O - 16 is more common.
The isotope most common in nature is O - 16 because the average atomic mass of oxygen is close to the mass of O - 16.

Step6: Explain use of isotopes in climate studies

Isotopes can act as tracers. Different isotopes have different physical and chemical properties that can be related to past climate conditions. For example, the ratio of oxygen - 18 to oxygen - 16 in ice cores can give information about past temperatures.
Scientists prefer isotopes instead of just measuring "oxygen atoms" in climate studies because isotopes can act as tracers and their ratios can provide information about past climate conditions.

Step7: Recall magnesium atomic number

Magnesium has an atomic number of 12. So for all magnesium isotopes, the number of protons = 12 and in neutral atoms, number of electrons = number of protons = 12.
For Mg - 24: Neutrons = 24 - 12 = 12.
For Mg - 25: Neutrons = 25 - 12 = 13.
For Mg - 26: Neutrons = 26 - 12 = 14.

Isotope	Protons	Neutrons	Electrons
Mg - 25	12	13	12
Mg - 26	12	14	12

Step8: Determine element

The element is magnesium.

Step9: Determine common magnesium isotope

The mass of the element is 24.4 amu which is close to 24 amu (the mass of Mg - 24). So Mg - 24 is the most abundant.
The most abundant isotope for this element is Mg - 24 because the average atomic mass of magnesium is close to the mass of Mg - 24.

Answer:

Isotope	Protons	Neutrons	Electrons
Carbon - 13	6	7	6
Carbon - 14	6	8	6

Carbon - 14 is still carbon because it has 6 protons, which defines the element carbon.
Carbon - 12

Isotope	Protons	Neutrons	Electrons
O - 17	8	9	8
O - 18	8	10	8

The isotope most common in nature is O - 16 because the average atomic mass of oxygen is close to the mass of O - 16.
Scientists prefer isotopes instead of just measuring "oxygen atoms" in climate studies because isotopes can act as tracers and their ratios can provide information about past climate conditions.

Isotope	Protons	Neutrons	Electrons
Mg - 25	12	13	12
Mg - 26	12	14	12

magnesium
The most abundant isotope for this element is Mg - 24 because the average atomic mass of magnesium is close to the mass of Mg - 24.