Element ______ has 2 valence electrons and is in period 4.

Answer:

I believe C

Explanation:

The absence of air between the two forms a vacuum seal which preserves the contents inside. I think that's right... good luck :)

Answer:

The answer is true.

Answer:

Average atomic mass of carbon = 12.01 amu

Explanation:

Given data:

Average atomic mass = ?

Percent abundance of C-12 = 98.93%

Percent abundance of C-13 = 1.07%

Solution:

Average atomic mass of carbon = (abundance of 1st isotope × its atomic mass) +(abundance of 2nd isotope × its atomic mass)  / 100

Average atomic mass of carbon = (98.93×12)+(1.07×13) /100

Average atomic mass of carbon=  1187.16 + 13.91 / 100

Average atomic mass of carbon = 1201.07/ 100

Average atomic mass of carbon = 12.01 amu

Answer:

Chain reaction

Explanation:

Answer:

the wind belt one

Explanation:

mhm

Answer:The USA lives in the Westerly Windbelt

Explanation:

Answer: Fluorine has the highest ionization enthalpy.

Explanation: This is because the ionization energy decreases from top to bottom and increases from left to right. Also, ionization enthalpy is the amount of energy required by an isolated gaseous atom to lose an electron in its ground state.

Since fluorine needs just one atom to attain noble gas configuration so it will not want to lose any electron and hence a high amount of energy will be required to remove an electron from it.

Answer:

backward, opposite, retrograde

Explanation:

why, i just got it right when i put that.

Answer:

here they are

Explanation:

Venus's rotation is backward compared to Earth's.

Venus's rotation is the opposite compared to Earth's.

Venus's rotation is retrograde compared to Earth's.

Answer:

c = 100 J/g.°C

Explanation:

Given data:

Mass of lime = 20 g

Heat absorbed = 80,000 J

Initial temperature = 10°C

Final temperature = 50°C

Specific heat capacity of lime = ?

Solution:

Specific heat capacity:

It is the amount of heat required to raise the temperature of one gram of substance by one degree.

Formula:

Q = m.c. ΔT

Q = amount of heat absorbed or released

m = mass of given substance

c = specific heat capacity of substance

ΔT = change in temperature

ΔT = 50°C - 10°C

ΔT = 40°C

80,000 J = 20 g×c×40°C

80,000 J = 800°C×c

c = 80,000 J /800g.°C

c = 100 J/g.°C

The specific heat capacity of the lime would be  is  c = 100 J/g.°C

The following formula should be used:

Q = m.c. ΔT

here

Q = amount of heat absorbed or released

m = mass of given substance

c = specific heat capacity of substance

ΔT = change in temperature

Now

ΔT = 50°C - 10°C

= 40°C

So,

80,000 J = 20 g×c×40°C

80,000 J = 800°C×c

c = 100 J/g.°C

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Answer:

i think it MIGHT be D

Explanation:

Answer:

b

Explanation:

edge :)

Answer:

It does not contain free mobile ions

Explanation:

Solid sodium chloride does not conduct electricity because it does not contain free mobile ions.

In solid state ions are arranged into crystal lattice and will not conduct a current of electricity.

Answer: They are chemically stable gases

Explanation:

Group 18 is also called the noble gases - because they have full valence shells it means they are stable and won't chemically react.

Answer:

1. Empirical formula => CH2O2

2. Molecular formula => C2H4O4

Explanation:

From the question given above, the following data were obtained:

Carbon (C) = 26.4 %

Hydrogen (H) = 3.3 %

Oxygen (O) = 70.3 %

Molar mass of compound = 91.0 g/mol

Empirical formula =..?

Molecular formula =..?

1. Determination of the empirical formula of the compound.

C = 26.4 %

H = 3.3 %

O = 70.3 %

Divide by their molar mass

C = 26.4 /12 = 2.2

H = 3.3 /1 = 3.3

O = 70.3 /16 = 4.39

Divide by the smallest

C = 2.2 /2.2 = 1

H = 3.3 /2.2 = 2

O = 4.39 /2.2 = 2

Empirical formula => CH2O2

2. Determination of the molecular formula of the compound.

Molar mass of compound = 91.0 g/mol

Empirical formula => CH2O2

Molecular formula => [CH2O2]n

We shall determine the value of n as follow:

[CH2O2]n = 91

[12 + (2×1) + (2×16)]n = 91

[12 + 2 + 32]n = 91

46n = 91

Divide both side by 46

n = 91/46

n = 2

Molecular formula => [CH2O2]n

Molecular formula => C2H4O4

In the given case where 26.4 % Carbon , 3.3 % Hydrogen , 70.3 % Oxygen , and Molar Mass: 91.0 g/mol the:

Given:

Carbon (C) = 26.4 %  

Hydrogen (H) = 3.3 %  

Oxygen (O) = 70.3 %  

Molar mass of compound = 91.0 g/mol  

Determination of the empirical formula of the compound:-

The ratio is CHO = 1 : 1.5 : 2

multiply with 2 to find correct and complete number ratio

C = 1 × 2 = 2

H = 1.5 × 2 = 3

O = 2 × 2 = 4

Thus,  the Empirical formula => [tex]C_2H_3O_4[/tex]

Mass × n = molar mass

12 × 2 + 1 × 3 + 16 × 4 = 91

24 + 3 + 64 = 91

91 = 91

Thus moles are 1 which means

molecular formula =  ([tex]C_2H_3O_4[/tex])[tex]_1[/tex]

Thus, here in the given data:

Molecular Formula: ([tex]C_2H_3O_4[/tex])[tex]_1[/tex]

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The characteristic of some repeating property can be used to find the answer is

The periodic table created by Mendeleev was initially based on the atomic weight of the elements, but he realized that the similarities of the atoms were greater if he used the atomic number, so he changed the ordering.

Mendeleev found that elements with the same number of electrons in their last shell had similar properties, when he ordered them he found that there were holes in the table, shortly after the work of many researchers the holes were completed and found numerous new chemical elements.

In the observation of the phases of the Moon around the earth it is found that for short measurements there are four phases, for longer measurements in addition to these four phases there are several higher repetition periods, with repeated observation the phases and periods are found. .

We can see that the two jobs are searched for, which is repeated and a table is created, leaving the spaces that are not known empty, with subsequent jobs filling these holes.

In conclusion, with the characteristics of some repeating property, the answer can be found is

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Mass of the product : 6.039 g

The reaction equation is the chemical formula of reagents and product substances

A reaction coefficient is a number in the chemical formula of a substance involved in the reaction equation. The reaction coefficient is useful for equalizing reagents and products

Reaction

Ba(s)+Cl₂(g)⇒BaCl₂(s)

mol Ba(MW=137,327 g/mol) :

[tex]\tt \dfrac{4}{137.327}=0.029[/tex]

Mass of BaCl₂ :(MW=208,23 g/mol)

[tex]\tt 0.029\times 208.23=6.039~g[/tex]

Answer:

c.

Explanation:

Gravitational potential energy will rises

the oxidation reaction between oxygen and sodium produces sodium oxide. In many cases, an element may form more than one oxide.

Explanation:

Answer:

Answer:

1. Positive

2. Negative

3. Positive

4. Negative

5 positive

Explanation: I did this test before

The words have a positive, negative, positive, negative, positive connotation respectively in each of the given sentence.

Connotation is defined as a property of a particular word or name  which describes the ideas or qualities of the word.It is rather being named explicitly or described.

It is frequently described as a positive or negative connotation  which is in connection with its pleasing or displeasing connection. Connotation can have words with literal meaning with what they specifically denote.

There are  two types of connotations positive connotation and negative connotation wherein positive connotation has  positive impact while negative connotation has negative impact.It describes the primary word and it is not necessary that it be present in the sentence or phrase.

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#SPJ2

Answer:

1.10 × 10⁻¹² m

General Formulas and Concepts:

Chemistry - Atomic Structure

Speed of Light = Wavelength times Frequency

Explanation:

Step 1: Define

ν  = 2.73 × 10²⁰ Hz

Step 2: Find wavelength

3.0 × 10⁸ m/s = λ(2.73 × 10²⁰ Hz)

λ = 1.0989 × 10⁻¹² m

Step 3: Check

We are given 3 sig figs. Follow sig fig rules.

1.0989 × 10⁻¹² m ≈ 1.10 × 10⁻¹² m

Answer:

its definitely A

Explanation:

hope this helps

Answer:

Coal is formed when dead plant matter submerged in swamp environments is subjected to the geological forces of heat and pressure over hundreds of millions of years. Over time, the plant matter transforms from moist, low-carbon peat, to coal, an energy- and carbon-dense black or brownish-black sedimentary rock.

Answer:

a) three pea halves

b) Electron configuration of the fluorine ion 1s2 2s2 2p6

Explanation:

The fluorine atom has seven electrons in its outermost shell and a total of nine electrons occupying three shells.

In the fluoride ion, the fluorine atom accepts one more electron to complete its outermost shell configuration (to have a filled shell as shown).

Hence the fluoride ion has 10 electrons with an electronic configuration of 1s2 2s2 2p6.

Answer:

E

Explanation:

Just e

Explanation:

canot understand the question

Answer:The units of molarity are M or mol/L. A 1 M solution is said to be “one molar.”

Explanation:

Answer:

mol/L

Explanation: