When writing the electron configuration for an element in the d block you have to remember to lower the energy level by 1.

Which of these has the most covalent character? <br> NaF Caf2 Bef2 CsF SrF2

Ksenya-84 [330]

Thus BeF2 is of most covalent character.

Anyways, covalent/ionic character is a bit tricky to figure out; we measure the difference in electronegativity of two elements bonding together and we use the following rule of thumb: if the charge is 0 (or a little more), the bond is non-polar covalent; if the charge is > 0 but < 2.0 (some references say 1.7), the bond is polar covalent; if the charge is > 2.0 then the bond is ionic. Covalent character refers to smaller electronegativity difference while ionic character refers to greater electronegativity difference.

Now, notice all of our bonds are with F, fluorine, which has the highest electronegativity of 3.98. This means that to determine character we need to consider the electronegativities of the other elements -- whichever has the greatest electronegativity has the least difference and most covalent character.
Na, sodium, has electronegativity of 0.93, so our difference is ~3 -- meaning our bond is ionic. Ca, calcium, has 1.00, leaving our difference to again be ~3 and therefore the bond is ionic. Be, beryllium, has 1.57 yielding a difference of ~2.5, meaning we're still dealing with ionic bond. Cs, cesium, has 0.79, meaning our difference is again ~3 and therefore again our compound is of ionic bond. Lastly, we have Sr, strontium, with an electronegativity of 0.95 and therefore again a difference of roughly 3 and an ionic bond. <span>
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3 0

3 years ago

A group of students is investigating whether aluminum is a better thermal conductor than steel. The students take an aluminum wi

Mademuasel [1]

The students have conducted an experiment to check their hypothesis on the thermal conductivity of two metals; Aluminum and steel. The experimental observations have been noted, and the next step based on the scientific procedure is to analyze the data.

Analysis of data suggests that; since the length of wax after 10 min is lower in Al than steel, aluminum is a better thermal conductor.

Ans B) Analyze the data

7 0

3 years ago

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Which of the following are produced when a base is dissolved in water?

Irina-Kira [14]

Answer is: B. Hydroxide ions.

An Arrhenius base is a substance that dissociates in water to form hydroxide ions (OH⁻).

For example sodium hydroxide: NaOH(aq) → Na⁺(aq) + OH⁻(aq).

Another example, balanced chemical reaction: Ba(OH)₂(aq) → Ba²⁺(aq) + 2OH⁻(aq).

According to the Arrhenius definition barium hydroxide is base.

Acids and bases when react (neutralisation) produce salt and water.

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3 years ago

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Based on the information, what is the balanced chemical equation representing the burning of butane?

kompoz [17]

Answer:

OptionA. 2C4H10 + 13O2 —> 8CO2 + 10H20

Explanation:

Butane burns is air (O2) according to the equation:

C4H10 + O2 —> CO2 + H20

Considering the equation, it is evident that it not balanced. Now let us balance the equation as shown below;

There are a total of 4 carbon atoms on the left and 1 carbon atom on the right. It can be balanced by putting 4 in front of CO2 as shown below:

C4H10 + O2 —> 4CO2 + H20

Next, there are 10 hydrogen atoms on the left and 2 hydrogen atoms on the right. Therefore to balance it, put 5 in front of H2O as shown below:

C4H10 + O2 —> 4CO2 + 5H20

Now, there are a total of 13 oxygen atoms on the right and 2 at the left. To balance it, put 13/2 in front of O2

as shown below

C4H10 + 13/2O2 —> 4CO2 + 5H20

Now we multiply through by 2 clear off the fraction and we obtained:

2C4H10 + 13O2 —> 8CO2 + 10H20

6 0

3 years ago

A dextrose/saline aqueaout solution doctors commonly use to replace fluids in the body contains 1.75g/L NaCl and 40.0g/L dextros

qwelly [4]

<em>Mixed molarity = 0.25 M</em>

<em>Osmotic pressure solution: 6.15 atm</em>

<h3><em>Further explanation</em></h3>

Osmotic pressure is the minimum pressure given to the solution so that there is no osmotic displacement from a more dilute solution to a more concentrated solution.

General formula:

$\large{\boxed {\bold {\pi \: = \: M \: x \: R \: x \: T}}}$

π = osmotic pressure (atm)

M = solution concentration (mol / l)

R = constant = 0.08205 L atm mol-1 K-1

T = Temperature (Kelvin)

Mixing solution

To find the molarity of the mixed solution we can use the following formula:

Vc. Mc = V1.M1 + V2.M2

where

Mc =Mixed molarity

Vc = mixed volume

Mr. NaCl = 58.5

Mr. Dextrose = C₆H₁₂O₆ = 180

mole NaCl = gram / Mr

mole NaCl = 1.75 / 58.5 = 0.03

Dextrose mole = 40/180 = 0.22

Assuming 1 liter of solution

M mixture = mole NaCl + mole dextrose / 1 liter

M mixture = 0.03 + 0.22 / 1 L

M mix = 0.25 M

T = 25 + 273 = 298 K

The osmosis pressure of the solution becomes:

π = 0.25. 0.0825. 298 = 6.15 atm

<h3><em>Learn more</em></h3>

The osmotic pressure brainly.com/question/8195553

<h3><em>Answer details </em></h3>

Grade: Senior High School

Subject: Chemistry

Chapter: Colligative property

Keywords: osmotic pressure, molarity, mole,dextrose, NaCl

7 0

3 years ago