What happens when a wave hits an object?

3. According to Newton's First Law of Motion, what does an object at rest do?

Taya2010 [7]

Answer:

stays at rest

Explanation:

7 0

3 years ago

1. For each of the molecules below, determine the electron geometry, molecule geometry, and bond

Alexxx [7]

Answer:

CCl4- tetrahedral bond angle 109°

PF3 - trigonal pyramidal bond angles less than 109°

OF2- Bent with bond angle much less than 109°

I3 - linear with bond angles = 180°

A molecule with two double bonds and no lone pairs - linear molecule with bond angle =180°

Explanation:

Valence shell electron-pair repulsion theory (VSEPR theory) helps us to predict the molecular shape, including bond angles around a central atom, of a molecule by examination of the number of bonds and lone electron pairs in its Lewis structure. The VSEPR model assumes that electron pairs in the valence shell of a central atom will adopt an arrangement which tends to minimize repulsions between these electron pairs by maximizing the distance between them. The electrons in the valence shell of a central atom are either bonding pairs of electrons, located primarily between bonded atoms, or lone pairs. The electrostatic repulsion of these electrons is reduced when the various regions of high electron density assume positions as far apart from each other as possible.

Lone pairs and multiple bonds are known to cause more repulsion than single bonds and bond pairs. Hence the presence of lone pairs or multiple bonds tend to distort the molecular geometry geometry away from that predicted on the basis of VSEPR theory. For instance CCl4 is tetrahedral with no lone pair and four regions of electron density around the central atom. This is the expected geometry. However OF2 also has four regions of electron density but has a bent structure. The molecule has four regions of electron density but two of them are lone pairs causing more repulsion. Hence the observed bond angle is less than 109°.

8 0

2 years ago

For the reaction: 3 H2(g) + N2(g) <--> 2 NH3(g), the concentrations at equilbrium were [H2] = 0.10 M, [N2] = 0.10 M, and [

masya89 [10]

The equilibrium constant, k of the reaction in which case, the concentrations of the given reactants and products are as indicated is; Choice A; K = 3.1 x 10⁵

<h3>What is the equilibrium constant , k of the reaction as described in the task content?</h3>

It follows from above that the concentrations of the reactants and products are as follows; [H2] = 0.10 M, [N2] = 0.10 M, and [NH3] = 5.6 M at equilibrium.

Hence, the equilibrium constant of the reaction in discuss is;

K = [5.6]²/[0.10]³[0.10]

k = 5.6² × 10⁴

k = 3.136 × 10⁵

K = 3.1 × 10⁵.

Read more on equilibrium constant;

brainly.com/question/1619133

#SPJ1

5 0

2 years ago

Which statements are true concerning elements in the same group of the periodic table? Select all that apply.

Tatiana [17]

The statements A and F are true concerning elements in the same group of the periodic table.

To select all that apply, we need to evaluate each statement.

A. They have similar periodic properties.

This statement is true. All the elements in the same group will have similar chemical and physical properties due to the electron configuration of their outer shell. For example, the alkali metals group (Li, Na, K, Rb, Cs, and Fr), has a valence electron configuration of s¹ (in the outer shell), which gives them the tendency to react vigorously with water, as well as other properties.

B. They are all metals or nonmetals, but not both.

This is false. If we take a look at the p-block of the periodic table, we can see that the <u>groups</u> in this block are conformed by nonmetals, metals, and metalloids. For example, the icosagens group is formed by metalloids (B) and metals (Al, Ga, In, Tl).

C. They are either all solids or all liquids or all gases.

This is false. In some groups, all the elements are solids (alkaline earth metals) or gases (group of noble gases), but in others, the groups are conformed by gases with solids (pnictogens group) or by gases with liquids (halogens group).

D. They have the same number of shells of electrons.

This is false. In a group, the number of shells <u>increases from top to bottom</u> in the periodic table. For example, the electron configuration of the elements in the alkali metals is:

H: 1s¹
Li: [He]2s¹
Na: [Ne]3s¹
K: [Ar]4s¹
Rb: [Kr]5s¹
Cs: [Xe]6s¹
Fr: [Rn]7s¹

We can see that hydrogen has 1 shell and Cs has 6 shells.

E. They have the same number of inner core electrons.

This is false. As we said at point D, the number of shells increases from top to bottom in a group, so the number of inner core electrons also increases in this order. For example, in the alkaline earth metals group, the electron configuration of the elements is:

Be: [He]2s²
Mg: [Ne]3s²
Ca: [Ar]4s²
Sr: [Kr]5s²
Ba: [Xe]6s²
Ra: [Rn]7s²

As we can see, the number of inner shells increases from Be ([He]) to Ra ([Rn]).

F. They have the same outer shell electron configuration.

This is true. As we said at point A, the elements in the same group will have the same electron configuration of the outer shell (valence electron configuration). At points D and E, we can see that the valence electron configuration is the same for all the elements in the groups.

Therefore, statements A and F are true.

You can find more about the periodic table here: brainly.com/question/4287157?referrer=searchResults

I hope it helps you!

6 0

3 years ago

An experiment looking at structures smaller than a cell would most likely employ a

Veseljchak [2.6K]

Answer:

In a conventional optical microscope, objects less than about 200 nanometers apart cannot be distinguished from one another. ... Although electron microscopes produce a detailed image of very small structures, they cannot provide an image of the proteins that make up those structures.

4 0

2 years ago