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Setler [38]
3 years ago
11

The first periodic table was organized according to atomic mass, but the current periodic table is arranged according to atomic

number. What is the difference between atomic mass and atomic number, and why is the atomic number now the basis for the periodic table?
Chemistry
1 answer:
MrMuchimi3 years ago
8 0

Answer: Atomic mass is associated with the number of neutrons and protons that are present in a particular nucleus of an element. Atomic number is usually the number of protons present in an element's nucleus. It is the average weight of an element. It is the total number of nucleons in the atom's nucleus.

Assuming there were errors in atomic masses, Mendeleev placed certain elements not in order of increasing atomic mass so that they could fit into the proper groups (similar elements have similar properties) of his periodic table.

- Have a nice day :)

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I'll mark brainliest.....
Ilya [14]
P = 203
V = 10
n = ?
R = 8.31
T = 298
PV = nRT \\ 203(10) = n(8.31)(298) \\ 2030 = 2476.38n \\ n =  \frac{2030}{2476.38} = 0.819 mol
5 0
3 years ago
Imagine two solutions with the same concentration and the same boiling point, but one has benzene as the solvent and the other h
11Alexandr11 [23.1K]

Complete question:

Imagine two solutions with the same concentration and the same boiling point, but one has benzene as the solvent and the other has carbon tetrachloride as the solvent. Determine that molal concentration, m (or b), and boiling point, Tb.

benzene boiling point=80.1 Kb=2.53

carbon tetrachloride boiling point=76.8 Kb=5.03

Answer:

m = 1.32 mol/kg

Boiling point: 83.4°C

Explanation:

When a nonvolatile solute is added to a pure solvent, the boiling point of the solvent increases, a phenomenon called ebullioscopy. This happens because of the interactions between the solute and the solvent. The temperature variation (new boiling point - normal boiling point) can be calculated by:

ΔT = m*Kb*i

Where m is the molal concentration (moles o solute/mass of solvent in kg), Kb is the ebullioscopy constant of the solvent, and i is the van't Hoff factor, which indicates how much of the solute dissociates. Let's assume that i is equal in both solvents and equal to 1 (the solvent dissociates completely)

Calling the new boiling point as Tb, for benzene:

Tb - 80.1 = m*2.53*1

Tb = 2.53m + 80.1

For carbon tetrachloride:

Tb - 76.8 = m*5.03*1

Tb = 5.03m + 76.8

Because Tb and m are equal for both:

5.03m + 76.8 = 2.53m + 80.1

2.5m = 3.3

m = 1.32 mol/kg

So, substituting m in any of the equations (choosing the first):

Tb = 2.53 * 1.32 + 80.1

Tb = 83.4°C

3 0
3 years ago
Read 2 more answers
How much kg is equal to what g
Marizza181 [45]

Answer:

1kg= 1000 grams hope it helps

6 0
3 years ago
CO
KonstantinChe [14]

Answer:

1) The number of the listed compounds that have ionic bonds between them are 5 compounds

2) Their formulas showing their charges within the compounds are;

NaCl ↔ Na⁺+Cl⁻

MgO ↔ Mg²⁺+O²⁻

K₂O ↔ 2K⁺+O²⁻

LiF ↔Li⁺+F⁻

CaO ↔ Ca⁺+O²⁻

3) The major reason they were selected is because they are compounds formed by the combination of a metal and a nonmetal

Explanation:

1) An ionic bond involves the transfer of an atoms valence to another atom, such that the ions formed by the ionic chemical bond will be oppositely charged

Therefore, metals, which are elements that mainly have a few electrons in their outermost shell, loses their valence electrons and become positively charged, while non metals, which require a few electrons to complete the stable octet electronic configuration, receive the electrons from the metallic atoms and become negatively charged

Therefore, the compounds formed between a metal and a nonmetal in the list are the the compounds containing ionic bonds, including

NaCl, MgO, K₂O, LiF, and CaO

Therefore, 5 compounds contain ionic bonds between them;

2) Their formulas are;

NaCl, MgO, K₂O, LiF, and CaO

3) The major reason that the chosen compounds contain ionic bonding between them is because they involve the combination of a metal and a nonmetal as follows;

a) NaCl → Na⁺ (metal ion) + Cl⁻(nonmetal ion)

b) MgO → Mg²⁺ (metal ion) + O²⁻(nonmetal ion)

c) K₂O → 2K⁺ (metal ion) + O²⁻(nonmetal ion)

d) LiF → Li⁺ (metal ion) + F⁻(nonmetal ion)

e) CaO → Ca⁺ (metal ion) + O²⁻(nonmetal ion)

6 0
3 years ago
Which of the following electron configurations are written incorrectly?
Lynna [10]

Answer:

The electronic configuration that are incorrectly written is 1s²2s³2p⁶, 4s²3d¹⁰4p⁷, 3s¹ and 2s²2p⁴.

Explanation:

The electronic configuration of the elements corresponds to how all the electrons of an element are arranged in energy levels and sub-levels.

There are 7 energy levels —from 1 to 7— whose sublevels are described as s, p, d and f.

All electronic configurations begin with the term "1s" —corresponding to the sublevel s of level 1— so 4s²3d¹⁰4p⁷, 3s¹ and 2s²2p⁴ are incorrectly written. In addition, 4s²3d¹⁰4p⁷ is written incorrectly because is impossible to jump from the sublevel "s" to the sublevel "d" —which is found from level 3 and up— without passing through the sublevel "p".

In the case of 1s²2s³2p⁶, the wrong thing is that the sublevel "s" can only hold two electrons, not three.

The other options are correctly written.

3 0
3 years ago
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