Question

practice

1. complete the table. the first row is done for you.

ion name	ion symbol	number of protons	number of electrons (in the ion)	atom gained or lost electrons to form the ion?	# energy levels of electrons in ion	electron configuration of which noble gas?
iodine		53	54		1
sulfur		16	18	gained
potassium				lost
calcium	ca²⁺	20
bromine	br⁻	35	36
strontium	sr²⁺	38	40
hydrogen	h⁺	1	0			(none)
oxygen	o²⁻	8		gained

1. write the symbol and charge for these transition metal ions:

cobalt (ii) ______
molybdenum (i) ______
chromium (iii) ______
manganese (iv) ______

1. write the name of these transition metal ions:

cu²⁺ ______
cr⁶⁺ ______
ti⁺ ______
pb³⁺ ______

Explanation:

Question 15 (Writing symbol and charge for transition metal ions)

Step 1: Cobalt (II)

The Roman numeral (II) indicates the charge is +2. The symbol for cobalt is Co. So the ion is $\text{Co}^{2+}$.

Step 2: Molybdenum (I)

Roman numeral (I) means charge +1. Symbol for molybdenum is Mo. Ion: $\text{Mo}^{+}$.

Step 3: Chromium (III)

Roman numeral (III) gives charge +3. Symbol Cr. Ion: $\text{Cr}^{3+}$.

Step 4: Manganese (IV)

Roman numeral (IV) means charge +4. Symbol Mn. Ion: $\text{Mn}^{4+}$.

Question 16 (Writing name of transition metal ions)

Step 1: $\text{Cu}^{2+}$

Copper has a charge of +2, so name is Copper (II) ion.

Step 2: $\text{Cr}^{6+}$

Chromium with charge +6, name: Chromium (VI) ion.

Step 3: $\text{Ti}^{+}$

Titanium with charge +1, name: Titanium (I) ion.

Step 4: $\text{Pb}^{3+}$

Lead with charge +3, name: Lead (III) ion.

Question 14 (Completing the table - let's take Oxygen as an example)

For Oxygen (O):

• Number of protons = 8 (atomic number of O).
• Since it gained electrons, and for O, typical ion is $\text{O}^{2-}$, so number of electrons = 8 + 2 = 10.
• Energy levels: O has electron configuration related to neon? Wait, O gains 2 electrons to have 10 electrons, same as Ne (neon has 10 electrons). So electron configuration of which noble gas? Neon.
• Number of energy levels of electrons in ion: O$^{2-}$ has electron configuration 1s² 2s² 2p⁶, so 2 energy levels? Wait, original O has 8 electrons, 2 in first, 6 in second. After gaining 2, 8 in second? Wait no, 2 in first, 8 in second? Wait 2 + 8 = 10. So energy levels: 2.

So for Oxygen row:

• Ion Symbol: $\text{O}^{2-}$ (since it gained 2 electrons, charge -2)
• Number of Electrons: 10
• Electron configuration of which noble gas: Neon (Ne)
• # energy levels of electrons in ion: 2

Final Answers (for Question 15):

• Cobalt (II): $\boldsymbol{\text{Co}^{2+}}$
• Molybdenum (I): $\boldsymbol{\text{Mo}^{+}}$
• Chromium (III): $\boldsymbol{\text{Cr}^{3+}}$
• Manganese (IV): $\boldsymbol{\text{Mn}^{4+}}$

Final Answers (for Question 16):

• $\text{Cu}^{2+}$: Copper (II) ion
• $\text{Cr}^{6+}$: Chromium (VI) ion
• $\text{Ti}^{+}$: Titanium (I) ion
• $\text{Pb}^{3+}$: Lead (III) ion

Final Answers (for Question 14 - Oxygen row):

• Ion Symbol: $\text{O}^{2-}$
• Number of Electrons: 10
• Electron configuration of which noble gas: Neon
• # energy levels of electrons in ion: 2

Answer:

Question 15 (Writing symbol and charge for transition metal ions)

Step 1: Cobalt (II)

The Roman numeral (II) indicates the charge is +2. The symbol for cobalt is Co. So the ion is $\text{Co}^{2+}$.

Step 2: Molybdenum (I)

Roman numeral (I) means charge +1. Symbol for molybdenum is Mo. Ion: $\text{Mo}^{+}$.

Step 3: Chromium (III)

Roman numeral (III) gives charge +3. Symbol Cr. Ion: $\text{Cr}^{3+}$.

Step 4: Manganese (IV)

Roman numeral (IV) means charge +4. Symbol Mn. Ion: $\text{Mn}^{4+}$.

Question 16 (Writing name of transition metal ions)

Step 1: $\text{Cu}^{2+}$

Copper has a charge of +2, so name is Copper (II) ion.

Step 2: $\text{Cr}^{6+}$

Chromium with charge +6, name: Chromium (VI) ion.

Step 3: $\text{Ti}^{+}$

Titanium with charge +1, name: Titanium (I) ion.

Step 4: $\text{Pb}^{3+}$

Lead with charge +3, name: Lead (III) ion.

Question 14 (Completing the table - let's take Oxygen as an example)

For Oxygen (O):

• Number of protons = 8 (atomic number of O).
• Since it gained electrons, and for O, typical ion is $\text{O}^{2-}$, so number of electrons = 8 + 2 = 10.
• Energy levels: O has electron configuration related to neon? Wait, O gains 2 electrons to have 10 electrons, same as Ne (neon has 10 electrons). So electron configuration of which noble gas? Neon.
• Number of energy levels of electrons in ion: O$^{2-}$ has electron configuration 1s² 2s² 2p⁶, so 2 energy levels? Wait, original O has 8 electrons, 2 in first, 6 in second. After gaining 2, 8 in second? Wait no, 2 in first, 8 in second? Wait 2 + 8 = 10. So energy levels: 2.

So for Oxygen row:

• Ion Symbol: $\text{O}^{2-}$ (since it gained 2 electrons, charge -2)
• Number of Electrons: 10
• Electron configuration of which noble gas: Neon (Ne)
• # energy levels of electrons in ion: 2

Final Answers (for Question 15):

• Cobalt (II): $\boldsymbol{\text{Co}^{2+}}$
• Molybdenum (I): $\boldsymbol{\text{Mo}^{+}}$
• Chromium (III): $\boldsymbol{\text{Cr}^{3+}}$
• Manganese (IV): $\boldsymbol{\text{Mn}^{4+}}$

Final Answers (for Question 16):

• $\text{Cu}^{2+}$: Copper (II) ion
• $\text{Cr}^{6+}$: Chromium (VI) ion
• $\text{Ti}^{+}$: Titanium (I) ion
• $\text{Pb}^{3+}$: Lead (III) ion

Final Answers (for Question 14 - Oxygen row):

• Ion Symbol: $\text{O}^{2-}$
• Number of Electrons: 10
• Electron configuration of which noble gas: Neon
• # energy levels of electrons in ion: 2