An atom's Lewis dot structure has three dots. Which of the following elements could it be, and why? (4 points) Group of answer choices

Aluminum, because it is in group 13 and has three valence electrons.

Lithium, because it is a group 1 element with three total electrons.

Magnesium, because it is in period 3 and has three valence electrons.

Potassium, because it is an alkali metal and has three inner shell electrons.

Answer : The correct option is, Magnesium because it is a group 2 element with two valence electrons.

Explanation :

Element = Calcium

Atomic number = 20

Electronic configuration of Ca =  

Number of valence electrons in Ca = 2

The number of inner shell electrons in Ca = 18

This option is wrong because lewis-dot structure shows only valence electrons not inner shell electrons.

Element = Carbon

Atomic number = 6

Electronic configuration of C =  

Number of valence electrons in C = 4

This option is wrong because only outermost p-sublevel electrons are not showing in lewis-dot structure.

Element = Lithium

Atomic number = 3

Electronic configuration of Li =  

Number of valence electrons in Li = 1

This option is wrong because it has only 1 electron in outermost shell.

Element = Magnesium

Atomic number = 12

Electronic configuration of Ma =  

Number of valence electrons in Ma = 3

This option is correct.

Lewis-dot structure : It is defined as the structure in which valence electrons of the atom is shown as dots.

ANOTHER EXPLANATION:

C. Magnesium, because it is a group 2 element with two valence electrons.

An atom's Lewis dot structure has two dots. Which of the following elements could it be, and why?

A. Calcium, because it is an alkaline earth metal with two inner shell electrons.

B. Carbon, because it has two electrons in its outermost p sublevel.

C. Lithium, because it is a group 1 element with two bonding electrons.

D. Magnesium, because it is a group 2 element with two valence electrons.

Explanation:

If you were to look at the periodic table magnesium would be in group 2. Since magnesium is in group 2 therefore it will have two valence electrons. Calcium is another possible answer because it is also in group two, but for this quiz it is incorrect. Lithium is incorrect because it is in group 1 and therefore it would only have 1 valence electron. Carbon is also incorrect because it is in group 14 so it would have 4 valence electrons. Hope this helps and makes sense.

Good Luck!!

Have a great day Studying!

Answer : The correct option is, Magnesium because it is a group 2 element with two valence electrons.

Explanation :

Element = Calcium

Atomic number = 20

Electronic configuration of Ca =  

Number of valence electrons in Ca = 2

The number of inner shell electrons in Ca = 18

This option is wrong because lewis-dot structure shows only valence electrons not inner shell electrons.

Element = Carbon

Atomic number = 6

Electronic configuration of C =  

Number of valence electrons in C = 4

This option is wrong because only outermost p-sublevel electrons are not showing in lewis-dot structure.

Element = Lithium

Atomic number = 3

Electronic configuration of Li =  

Number of valence electrons in Li = 1

This option is wrong because it has only 1 electron in outermost shell.

Element = Magnesium

Atomic number = 12

Electronic configuration of Ma =  

Number of valence electrons in Ma = 3

This option is correct.

Lewis-dot structure : It is defined as the structure in which valence electrons of the atom is shown as dots.

ANOTHER EXPLANATION:

C. Magnesium, because it is a group 2 element with two valence electrons.

An atom's Lewis dot structure has two dots. Which of the following elements could it be, and why?

A. Calcium, because it is an alkaline earth metal with two inner shell electrons.

B. Carbon, because it has two electrons in its outermost p sublevel.

C. Lithium, because it is a group 1 element with two bonding electrons.

D. Magnesium, because it is a group 2 element with two valence electrons.

Explanation:

If you were to look at the periodic table magnesium would be in group 2. Since magnesium is in group 2 therefore it will have two valence electrons. Calcium is another possible answer because it is also in group two, but for this quiz it is incorrect. Lithium is incorrect because it is in group 1 and therefore it would only have 1 valence electron. Carbon is also incorrect because it is in group 14 so it would have 4 valence electrons. Hope this helps and makes sense.

Explanation:

when 25.0 ml of 0.700 mol/l naoh was mixed in a calorimeter with 25.0 ml of 0.700 mol/l hcl, both initially at 20.0 °c, the temperature increased to 22.1 °c. the heat capacity of the calorimeter is 279 j/°c.

the equation for the reaction is:

naoh + hcl → nacl + h₂o

moles of hcl = 0.0250 l hcl ×

0.700

mol hcl

1 l hcl = 0.0175 mol hcl

volume of solution = (25.0 + 25.0) ml = 50.0 ml

mass of solution = 50.0 ml soln ×

1.00

ml soln

= 50.0 g soln

δt=t2-t1

= (22.1 – 20.0) °c = 2.1 °c

the heats involved are

heat from neutralization + heat to warm solution + heat to warm calorimeter = 0

q1+q2+q3=0

nδh+mcδt+cδt=0

0.0175 mol ×

δh

+ 50.0 g × 4.184 j·g⁻¹°c⁻¹ × 2.1 °c + 279 j°c⁻¹ × 2.1 °c = 0

0.0175 mol ×

δh

+ 439.32 j + 585.9 j = 0

0.0175 mol ×

δh

= -1025.22 j

δh=1025.22j0.0175 mol= -58 600 j/mol = -58.6 kj/mol

the answer is b. dilution