Chemistry Atomic Structure

1. What is the mass, charge, and location for an electron:
Mass: Negligible, about 1/2000u
Charge: Negative
Location: Orbitals

2. What is the mass, charge, and location for a neutron:
Mass: 1u
Charge: No charge
Location: Nucleus

3. What is the mass, charge, and location for a proton:
Mass: 1u
Charge: Positive
Location: Nucleus

4. Which subatomic particle identifies the element and acts like a social security number:
Proton

5. Which scientist said the atom was a solid indivisible sphere:
Dalton

6. Which scientist is credited for discovering the electron using a cathode ray tube:
JJ Thomson

7. What were two conclusions discovered from Rutherford’s Gold-Foil Experiment:

  1. The atom is mostly empty space.

  2. There is a small, dense, positive nucleus.

8. Which model of the atom has electrons orbiting the nucleus in fixed locations:
Bohr Model

9. Which model of the atom has electrons orbiting the nucleus in probable locations:
Modern Model (Quantum Mechanical Model)

10. Why is the nucleus of the atom dense:
The nucleus contains protons and neutrons, which have significant mass.

11. What is the charge of the nucleus:
Positive

12. What is an isotope:
Isotopes are atoms of the same element with different mass numbers due to varying numbers of neutrons (e.g., H-1, H-2, H-3).

13. What does the "14" in O-14 represent, and how many neutrons does O-14 have:
The "14" is the mass number, which is the sum of protons and neutrons. Oxygen has 8 protons, so O-14 has 6 neutrons.

14. How many neutrons does C-14 have:
6 neutrons

15. How many neutrons does N-16 have:
9 neutrons

16. What is an ion:
An ion is an atom or molecule that has an unequal number of protons and electrons, resulting in a net charge.

17. Is P-3 an element or an ion:
P-3 is an ion because it has more electrons (18) than protons (15).

18. Determine and explain the protons and neutrons for O-2:
Oxygen (O) has 8 protons. O²⁻ has 10 electrons due to its -2 charge (2 extra electrons).

19. What is an atom:
The smallest part of an element that is electrically neutral, with equal numbers of protons and electrons.

20. What does the atomic number represent:
The number of protons in an element.

21. How can you determine the mass number for an element:
By adding the number of protons and neutrons.

22. What charge do elements and compounds have:
They are usually neutral unless they form ions.

23. How do you determine the charge of a substance:
By comparing the number of protons and electrons.

24. Which element always has 8 protons:
Oxygen

25. What does a neutral charge mean, or what does it mean when an atom is neutral:
A neutral atom has equal numbers of protons and electrons, so their charges balance out.

26. What is the difference between atomic mass and mass number:

  • Mass Number: Total number of protons and neutrons (always a whole number).

  • Atomic Mass: Weighted average of all isotopes (often a decimal).

27. Why is the mass of the N-16 isotope 16u, while the atomic mass of nitrogen on the reference table is 14.0067u:
N-16 refers to a specific isotope of nitrogen with 7 protons and 9 neutrons. The atomic mass on the table is the weighted average of all nitrogen isotopes, primarily N-14.

28. Compare/contrast an atom of sulfur and an ion of sulfur with a charge of -2 (S-2):

  • Atom of sulfur: Neutral with equal protons and electrons.

  • S-2 ion: Gains 2 extra electrons, making it negatively charged.

29. Give the order and a brief description of each model of the atom:

  1. Dalton: Hard indivisible sphere.

  2. Thomson: Discovered the electron using a cathode ray tube.

  3. Rutherford (Gold Foil Experiment): Atom is mostly empty space with a small, dense nucleus.

  4. Bohr Model: Electrons orbit in fixed locations.

  5. Modern Model: Electrons are in probable locations called orbitals.

30. How can a neutral atom of oxygen have 8 electrons when the reference table lists oxygen as typically having a charge of -2:
A neutral oxygen atom has 8 protons and 8 electrons. In compounds, oxygen typically gains 2 electrons, leading to a -2 charge.

  1. What are valence electrons?: Valence electrons are the last number of the elements electron configuration, outermost electrons, and influences the element’s chemical properties. No longer occupies the lowest available energy levels

  2. Which elements have the same valence electrons?: Elements in the same group have the same valence electrons and have similar chemical properties

  3. What does PLENGE stand for?: Positive Lose Electrons Negative Gain Electrons

  4. Where to find ground state configuration of an element?: Periodic Table

  5. Compare and contrast Ground state and excited state: Comparison is that ground state and excited state have the same number of electrons. Contrast is that excited state has one electron that has moved to a higher level/orbital

  6. How many electrons can the first shell hold and how many can the rest hold?: 2 electrons, 8 electrons

  7. Relationship between the distance from the nucleus and the energy the electron has: the greater the distance from the electron the more energy the electron has