Question

quiz: first 20 elements, atomic structure, and periodic
write the element name or symbol?

1. ca
2. potassium
3. ar
4. chlorine
5. sulfur
6. phosphorus
7. si
8. al
9. magnesium
10. na
11. ne
12. fluorine
13. be
14. helium
15. c

fill in blank/short answer

1. a horizontal row on the periodic table is called a
2. a vertical column on the periodic table is called a
3. the electrons in the outermost energy level are called

electrons.

1. the atomic number represents the number of
2. potassium has 19 protons, 19 neutrons and 19 electrons. what is the

atomic mass of potassium?

1. magnesium has 12 protons, 22 neutrons, and 12 electrons. what is the

atomic number of magnesium? what is the atomic mass of
magnesium?

1. how many atoms are in h₂so₄?
2. how many atoms are in 4(nh₄)₂so₄?
3. draw a bohr model for aluminum (atomic number is 13).

Explanation:

Step1: Recall element names and symbols

1. Calcium
2. K
3. Argon
4. Cl
5. S
6. P
7. Silicon
8. Aluminum
9. Mg
10. Sodium
11. Neon
12. F
13. Beryllium
14. He
15. Carbon

Step2: Answer periodic - table related questions

1. Period
2. Group
3. Valence
4. Protons

Step3: Calculate atomic mass

1. Atomic mass = protons + neutrons, so for potassium with 19 protons and 19 neutrons, atomic mass = 19 + 19=38
2. Atomic number of magnesium is 12 (number of protons), atomic mass = 12 + 22 = 34

Step4: Count atoms in compounds

1. In \(H_2SO_4\), there are 2 H + 1 S+4 O = 7 atoms
2. In \(4(NH_4)_2SO_4\), first in \((NH_4)_2SO_4\): 2 N + 8 H+1 S + 4 O=15 atoms, then for \(4(NH_4)_2SO_4\), there are \(4\times15 = 60\) atoms

Step5: Note on drawing Bohr - model

1. For aluminum (atomic number 13), there are 13 protons in the nucleus. First shell has 2 electrons, second shell has 8 electrons and third shell has 3 electrons. (Since drawing is not possible in this text - based format, the electron - shell distribution is described)

Answer:

1. Calcium
2. K
3. Argon
4. Cl
5. S
6. P
7. Silicon
8. Aluminum
9. Mg
10. Sodium
11. Neon
12. F
13. Beryllium
14. He
15. Carbon
16. Period
17. Group
18. Valence
19. Protons
20. 38
21. 12, 34
22. 7
23. 60
24. Nucleus with 13 protons, first shell 2 electrons, second shell 8 electrons, third shell 3 electrons