Someone pls help me with this before i k word myself

Question 9 rank the effective nuclear charge z * experienced by a valence electron in each of these atoms:

AlexFokin [52]

To rank the effective nuclear charge Z* experienced by a valence electrons of a set of atoms that belong to a same period, you only need to apply the rule of trend: it increases as you move from left to right in the period.

So, lets do it for these atoms: P, Al, Si, Cl

The belong to a same period and the order is Al, Si, P, Cl (just see a periodic table). So the rank is Al < Si < P < Cl

Now, lets do it for these atoms:, Be, Ne, O, C

They belong to the second period. The order is Be, C, O, Ne

So, the rank is Be < C < O < Ne.

7 0

3 years ago

Can we be friends ????

Svet_ta [14]

Yes of course!!!! :)

5 0

2 years ago

Explain on any two materials that you would expect to use for the wheelchair (both back support and

Ugo [173]

Answer:

In the backrest use materials where it is easy to clean and where they do not absorb fluids, in this way it would be cooler, such as an ecological leather simulator.

And in the armrest as well, but in both areas we must not rule out that if or if it should have even a minimum of padded surface so that the patient or the person who spends most of the day in the wheelchair does not suffer from joint pain.

Explanation:

Some wheelchair factories also implement modern chairs where they are made of stainless steel structures lined with padded material with perforated fabrics that allow breathing and aeration of body areas that have contact with the fabric.

8 0

3 years ago

In which of the following compounds does the carbonyl stretch in the IR spectrum occur at the lowest wavenumber?

klio [65]

Answer:

a. Cyclohexanone

Explanation:

The principle of IR technique is based on the vibration of the bonds by using the energy that is in this region of the electromagnetic spectrum. For each bond, there is a specific energy that generates a specific vibration. In this case, you want to study the vibration that is given in the carbonyl group C=O. Which is located around 1700 cm-1.

Now, we must remember that the lower the wavenumber we will have less energy. So, what we should look for in these molecules, is a carbonyl group in which less energy is needed to vibrate since we look for the molecule with a smaller wavenumber.

If we look at the structure of all the molecules we will find that in the last three we have heteroatoms (atoms different to carbon I hydrogen) on the right side of the carbonyl group. These atoms allow the production of resonance structures which makes the molecule more stable. If the molecule is more stable we will need more energy to make it vibrate and therefore greater wavenumbers.

The molecule that fulfills this condition is the cyclohexanone.

See figure 1

I hope it helps!

4 0

3 years ago

If the metal in the ionic compound is a transition element (with variable charge metal ions), the ionic charge is written as a R

spayn [35]

Answer : The name of ionic compound is, Copper(II) fluoride.

Explanation :

Ionic compound : It is defined as the compound which is formed when electron gets transferred from one atom to another atom.

Ionic compound are usually formed when a metal reacts with a non-metal.

The nomenclature of ionic compounds is given by:

1. Positive ion is written first.

2. The negative ion is written next and a suffix is added at the end of the negative ion. The suffix written is '-ide'.

3. In case of transition metals, the oxidation state are written in roman numerals in bracket in-front of positive ions.

$CuF_2$

$CuF_2$ is an ionic compound because copper element is a metal and fluorine element is a non-metal. The bond formed between a metal and a non-metal is always ionic in nature.

The oxidation state of copper in $CuF_2$ is, (+2)

Thus, the name of ionic compound is, Copper(II) fluoride.

8 0

3 years ago