What is the oxidation number for N in the compound NH3? (Recall that H usually has an oxidation number of +1.)

Can I please know What are the answers for #s 1,2,3,4 ?

dimulka [17.4K]

1 wavelength, 2 crest, 3 trough, 4 wave height <3

8 0

3 years ago

Given the formula representing a compound: what is a chemical name of this compound? 2-pentene 2-pentyne 3-pentene 3-pentyne

Aleks [24]

The question is incomplete. Complete question is attached below.
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Correct Answer: Option 1) 2-pentene

Reason:
Following are the IUPAC rules for naming the compound
1) Select the longest carbon chain. In present case longest carbon chain has 5 carbon atom. Hence, it is a pentane derivative.
2) In case of alkene, replace 'e' of alkane by 'ene'
3) Give lowest number to function group. In present case, it is double bond.

Applying above rules, the IUPAC name of compound is 2-pentene

4 0

3 years ago

What tool do you use to measure a rectangle?

pashok25 [27]

Answer:

Ruler

Explanation:

3 0

3 years ago

Read 2 more answers

Calculate the molality of a solution formed by adding 6.30 g NH4CL to 15.7 g of water

babymother [125]

Answer:

Molality = 7.5 mol/kg

Explanation:

Given data:

Mass of NH₄Cl = 6.30 g

Mass of water = 15.7 g (15.7/1000 =0.016 kg)

Molality = ?

Solution:

Formula of molality:

Molality = Moles of solute / mass of solvent in gram

Now we will first calculate the number of moles of solute( NH₄Cl )

Number of moles = mass/ molar mass

Molar mass of NH₄Cl = 53.491 g/mol

Number of moles = 6.30 g/ 53.491 g/mol

Number of moles = 0.12 mol

Now we will calculate the molality.

Molality = Moles of solute / mass of solvent in gram

Molality = 0.12 mol / 0.016 kg

Molality = 7.5 m

or (m=mol/kg)

Molality = 7.5 mol/kg

6 0

3 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 groups 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 increases from top to bottom 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