Question

1. in which energy level are the outermost electrons of iodine?
2. where are the metals located on the periodic table?
3. where are the nonmetals?
4. which group of elements is least reactive? why are they unreactive?

part 2: ions

1. what is a “cation” and how does an atom become a cation?
2. what is an “anion” and how does an atom become an anion?
3. how does the number of valence electrons help you determine if an atom will make a cation or an anion?
4. why do atoms gain or lose electrons to make ions?
5. complete the table. it continues on the following page:
6. select the combination of words that fill in the blanks in the following statement in the correct order. metals tend to ____________ electrons to become more stable and form __________. nonmetals tend to __________ electrons to become more stable and form ____________.

element	name of element	valence electrons	e- gained or lost to form octet (8 ve)	symbol of ion	anion or cation
na	sodium	1ve	lose 1	na⁺	cation
al
cl

Explanation:

Step1: Recall iodine's position

Iodine is in the 5th period of the periodic table. The outermost electrons are in the energy - level corresponding to its period number.

Step2: Determine the energy level

So the outermost electrons of iodine are in the 5th energy level.

Step3: Locate metals on periodic table

Metals are located on the left - hand side and in the middle (transition metals) of the periodic table.

Step4: Locate non - metals

Non - metals are located on the right - hand side of the periodic table.

Step5: Identify least reactive group

The noble gases (Group 18) are the least reactive. They have a full outer shell of electrons, which gives them a stable electron configuration.

Step6: Define cation

A cation is a positively charged ion. An atom becomes a cation by losing one or more electrons.

Step7: Define anion

An anion is a negatively charged ion. An atom becomes an anion by gaining one or more electrons.

Step8: Explain valence electrons role

If an atom has 1 - 3 valence electrons, it is likely to lose electrons to form a cation. If it has 5 - 7 valence electrons, it is likely to gain electrons to form an anion. Atoms with 4 valence electrons may form covalent bonds.

Step9: Explain ion formation

Atoms gain or lose electrons to make ions to achieve a stable electron configuration, usually a full outer shell (octet rule for most elements).

Step10: Complete table for Na

Sodium (Na) has 1 valence electron. It loses 1 electron to form $Na^+$, a cation.

Step11: Complete table for Al

Aluminum (Al) has 3 valence electrons. It loses 3 electrons to form $Al^{3 + }$, a cation.

Step12: Complete table for Cl

Chlorine (Cl) has 7 valence electrons. It gains 1 electron to form $Cl^-$, an anion.

Step13: Fill in blanks

Metals tend to lose electrons to become more stable and form cations. Nonmetals tend to gain electrons to become more stable and form anions.

Answer:

1. 5th energy level
2. Left - hand side and middle (transition metals) of the periodic table
3. Right - hand side of the periodic table
4. Noble gases (Group 18); they have a full outer shell of electrons
5. A cation is a positively charged ion; an atom becomes a cation by losing one or more electrons
6. An anion is a negatively charged ion; an atom becomes an anion by gaining one or more electrons
7. If an atom has 1 - 3 valence electrons, it is likely to lose electrons to form a cation. If it has 5 - 7 valence electrons, it is likely to gain electrons to form an anion. Atoms with 4 valence electrons may form covalent bonds.
8. To achieve a stable electron configuration (usually a full outer shell - octet rule for most elements)

20.

Element	name of element	Valence electrons	e - gained or lost to form octet (8 VE)	Symbol of ion	Anion or cation
Na	Sodium	1	lose 1	$Na^+$	Cation
Al	Aluminum	3	lose 3	$Al^{3 + }$	Cation
Cl	Chlorine	7	gain 1	$Cl^-$	Anion

1. lose; cations; gain; anions