Question

directions: as you prepare for your test, you should review your notes, homework, and quizzes. your textbook should be your source of definitions for vocabulary. if you are unsure of anything or have questions, you can reach out to your teacher for extra help. the questions on this review are intended to be a sample of the various types of questions you may encounter on the test. the actual number of questions and questions themselves will be unique on test day. your ability to answer these questions are a good indication of how prepared you are for the test. good luck! 1.) which of the subatomic particles has a relative mass of ~0? a) proton b) neutron c) moron d) electron 2.) what is the atomic number of helium (he)? 3.) what is the atomic mass of lithium (li)? 4.) which of the following is true of an atom of ¹³c? it has: a) 13 neutrons b) 13 protons c) 7 protons d) 7 neutrons 5.) the atoms ¹³c and ¹²c are ______ of one another a) isotopes b) ions c) compounds d) mixtures label the parts of the atom on the diagram below: complete the chart below using the information provided and a periodic table: isotope name notation protons neutrons electrons mass number atomic number isotopic symbol notation carbon - 14 6 ¹⁴₆c 18 19 23 48 ⁸¹₃₅br 37 37 17 17 ⁴¹₂₀ca

Explanation:

Step1: Recall sub - atomic particle masses

Protons and neutrons have a relative mass of approximately 1. Electrons have a relative mass of ~0. So for question 1, the answer is d) electron.

Step2: Recall atomic number concept

The atomic number of an element is the number of protons in its nucleus. Helium has 2 protons, so its atomic number is 2 for question 2.

Step3: Recall atomic mass from periodic table

Looking at the periodic table, the atomic mass of lithium (Li) is approximately 6.94 for question 3.

Step4: Analyze carbon - 13 composition

For an atom of \(^{13}C\), the mass number is 13. The atomic number of carbon is 6 (number of protons). Number of neutrons = mass number - atomic number = 13 - 6=7. So for question 4, the answer is d) 7 neutrons.

Step5: Recall isotope definition

Atoms \(^{13}C\) and \(^{12}C\) have the same number of protons but different numbers of neutrons. They are isotopes of one another for question 5. So the answer is a) isotopes.

For the atom - labeling part:
The positively charged particles in the center are protons. The uncharged particles in the center are neutrons. The negatively charged particles outside the center are electrons.

For the chart:

• For Carbon - 14: Atomic number of carbon is 6, so number of protons = 6. Mass number = 14, number of neutrons=mass number - atomic number = 14 - 6 = 8. In a neutral atom, number of electrons = number of protons = 6. Isotopic symbol notation is \(^{14}_6C\).
• For the row with 18 protons and 19 neutrons: Atomic number = 18 (element is argon, Ar). Mass number=protons + neutrons = 18+19 = 37. Number of electrons in a neutral atom = 18. Isotopic symbol notation is \(^{37}_{18}Ar\).
• For the row with 23 electrons and 48 mass number: In a neutral atom, number of protons = number of electrons = 23 (element is vanadium, V). Number of neutrons=mass number - atomic number = 48 - 23 = 25. Isotopic symbol notation is \(^{48}_{23}V\).
• For \(^{81}_{35}Br\): Number of protons = 35, number of neutrons=81 - 35 = 46, number of electrons in a neutral atom = 35.
• For the row with 37 protons and 37 neutrons: Atomic number = 37 (element is rubidium, Rb). Mass number=37 + 37=74. Number of electrons in a neutral atom = 37. Isotopic symbol notation is \(^{74}_{37}Rb\).
• For \(^{41}_{20}Ca\): Number of protons = 20, number of neutrons=41 - 20 = 21, number of electrons in a neutral atom = 20.

Answer:

1. d) electron
2. 2
3. Approximately 6.94
4. d) 7 neutrons
5. a) isotopes

Atom - labeling: Protons in center (positively charged), neutrons in center (uncharged), electrons outside center (negatively charged)
Chart:

Isotope name notation	Protons	Neutrons	Electrons	Mass number	Atomic number	Isotopic Symbol notation
-	18	19	18	37	18	\(^{37}_{18}Ar\)
-	23	25	23	48	23	\(^{48}_{23}V\)
\(^{81}_{35}Br\)	35	46	35	81	35	\(^{81}_{35}Br\)
-	37	37	37	74	37	\(^{74}_{37}Rb\)
\(^{41}_{20}Ca\)	20	21	20	41	20	\(^{41}_{20}Ca\)