All categories

3 years ago

Please be I need this quick

Chemistry

1 answer:

Marizza181 [45]3 years ago

3 0

Answer: Option (A) is the correct answer.

Explanation:

An atom who has seven valence electrons in its ground state will have the following electronic configuration in its sub shells as 2, 7.

Thus, there will be in total 9 electrons and it is known that fluorine has atomic number 9.

Whereas sodium has 2, 8, 1 electrons in its sub-shell.

Calcium has 2, 8, 8, 2 electrons in its sub-shell and oxygen has 2, 6 electrons in its sub-shell.

Thus, we can conclude that out of the given options, fluorine is the element whose atom in the ground state has seven valence electrons.

You might be interested in

Which actions represent endothermic reactions? Check all that apply. an instant ice pack becoming cold, splitting a gas molecule

DerKrebs [107]

Answer is: an instant ice pack becoming cold, splitting a gas molecule and baking bread.

Endothermic reaction is chemical reaction that absorbs more energy than it releases.
In ice pack, reaction absorbs heat from the surroundings (endothermic reaction), lowering the surrounding temperature.
For splitting molecule and baking bread we must add energy to break bonds between atoms.

6 0

3 years ago

Read 2 more answers

There are two naturally occurring isotopes of indium: indium-113 and indium-115. How many neutrons are in a single atom of indiu

KonstantinChe [14]

There are 66 neutrons in a single atom of indium-115. The atomic number of indium-115 is 49, meaning there are 49 protons. Then the atomic mass is 115, so 115-49 = 66.

5 0

3 years ago

An atom of which of these elements most likely forms an anion? A. AI B. Br C. Ca D. Mg

Papessa [141]

The answer is B. A good way determine this is how far right the element is on the periodic table. The further right the element is, the more electronegative it is meaning it is more willing to accept an electron. This can be explained using the valence electrons and how many need to be added or removed to complete the octet. The further right you are, the easier it is for the element to just gain a few electrons instead of loose a bunch. Noble gases are the exception to this since they don't normally react though.

4 0

3 years ago

Read 2 more answers

1. A mixture of 3 gases (A, B, and C) has a total pressure of 240kPa. If the partial pressure of

Gala2k [10]

Answer:

78 kPa

Explanation:

The total pressure is the sum of the partial pressures:

240 = Pa + Pb + Pc

240 = 107 + 55 + Pc

Pc = 78 kPa

5 0

3 years ago

Read 2 more answers

A student is asked to determine the molarity of a strong base by titrating it with 0.250 M solution of H2SO4. The students is in

tamaranim1 [39]

Answer:

The molarity of the strong base is 0.625 M

Which procedural error will result in a strong base molarity that is too high?

⇒ Using a buret with a tip filled with air rather than the H2SO4 solution

Explanation:

Step 1: Data given

Molarity of H2SO4 = 0.250 M

The initial buret reading is 5.00 mL

The final reading is 30.00 mL

Step 2: Calculate volume of H2SO4 used

30.00 mL - 5.00 mL = 25.00 mL

Step 3: Calculate moles of H2SO4

0.250 M = 0.250 mol/L

Since there are 2 H+ ions per H2SO4

0.250 mol/L * 2 = 0.500 mol/L

The number of moles H2SO4 = 0.500 mol/L * 0.025 L

Number of moles H2SO4 = 0.0125 mol

Step 4: Calculate moles of OH-

For 1 mol H2SO4, we need 1 mol of OH-

For 0.0125 mol of H2SO4, we have 0.0125 mol of OH-

Step 5: Calculate the molarity of the strong base

Molarity = moles / volume

Molarity OH- = 0.0125 mol / 0.02 L

Molarity OH - = 0.625 M

Which procedural error will result in a strong base molarity that is too high?

⇒ Using a buret with a tip filled with air rather than the H2SO4 solution

5 0

3 years ago