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Nadya [2.5K]
3 years ago
12

Scientists are certain that there are no undiscovered elements missing from the periodic table from hydrogen to lawrencium.

Chemistry
2 answers:
leva [86]3 years ago
7 0

Answer:

Because no free places exist known and the succession of elements in the periodic table is very rational explained: increasing of number of electrons with 1, spectral data, chemical properties similarities

Explanation: i just did the test

Soloha48 [4]3 years ago
4 0

Answer:

Explanation:

You are talking about the first 103 elements. An element is by definition identified with the number of protons in its nucleus, the so-called atomic number. Any atom with 6 protons is carbon, it cannot be anything else. So there cannot be any missing elements out to 103, as all of these elements have been confirm discovered by accepted scientific methods.

For example, here is a link to a CHEM Study film showing how transuranium elements (i.e. atomic number > 92 and man-made) can be separated from one another and verified as distinct.

You might be interested in
Which identifies an oxidation-reduction reaction?
Alchen [17]

The statement that identifies an oxidation-reduction reaction is a reaction in which oxidation numbers change (option C).

<h3>What is a redox reaction?</h3>

A redox or oxidation-reduction reaction is a chemical reaction in which some of the atoms have their oxidation number changed.

In a chemical reaction that involves oxidation and reduction, the oxidation number of the involved ions either decreases or increases.

Therefore, the statement that identifies an oxidation-reduction reaction is a reaction in which oxidation numbers change.

Learn more about redox reaction at: brainly.com/question/13293425

#SPJ1

6 0
2 years ago
At room temperature (20°C} and pressure, the density of air is 1.189 g/L. An object will float in air if its density is less tha
Alekssandra [29.7K]

Explanation:

Density =\frac{Mass}[Volume}

Density of the air ,d= 1.189 g/L

(a) Density of the evacuated ball

Mass of the ball ,m = 0.12 g

Volume of the ball =V=560 cm^3=560 ml=0.560 L

D =\frac{0.12 g}{0.560 L}=0.214 g/L

D<d, teh evacuated ball will flaot in air.

(b) Density of the evacuated ball D = 0.214 g/L

Density of carbon dioxide gas = d_1=1.830 g/L

Mass of the carbon dioxide gas :

1.830 g/L\times 0.560 L=1.0248 g

Total density of filled ball with carbon dioxide gas:

\frac{0.12 g+1.0248 g}{0.560 L}==2.044 g/L

The ball filled with carbon dioxide will not float in the air because total density of filled ball is greater than the density of an air.

(c) Density of the evacuated ball D = 0.214 g/L

Density of hydrogen gas = d_2=0.0899 g/L

Mass of the hydrogen gas :

1.830 g/L\times 0.560 L=0.050344 g

Total density of filled ball with hydrogen gas:

\frac{0.12 g+0.050344 g}{0.560 L}==0.3041 g/L

The ball filled with hydrogen will float in the air because total density of filled ball is lessor than the density of an air.

(d) Density of the evacuated ball D = 0.214 g/L

Density of oxygen gas = d_3=1.330 g/L

Mass of the oxygen gas :

1.330 g/L\times 0.560 L=1.7448 g

Total density of filled ball with oxygen gas:

\frac{0.12 g+1.7448 g}{0.560 L}=1.5442 g/L

The ball filled with oxygen will not float in the air because total density of filled ball is greater than the density of an air.

(e) Density of the evacuated ball D = 0.214 g/L

Density of nitrogen gas = d_4=1.165 g/L

Mass of the nitrogen gas :

1.165 g/L\times 0.560 L=0.6524 g

Total density of filled ball with nitrogen gas:

\frac{0.12 g+0.6524 g}{0.560 L}==1.3792 g/L

The ball filled with nitrogen will not float in the air because total density of filled ball is greater than the density of an air.

f) Mass must be added to sink the ball = m

Density of ball > Density of the air ; to sink the ball.

\frac{0.12g +m}{0.560L}>1.189 g/L

m > 0.54584 g

For any case weight added to ball to make it sink in an air should be grater than the value of 0.54584 grams.

5 0
2 years ago
Help help help help help
dimaraw [331]

Answer:

neon gas

Explanation:

neon is a noble gas, meaning it has a full outer shell of elections. this means it is stable and is very unlikely to have a reaction with another substance.

7 0
2 years ago
What has 6 valence electrons and 16 protons and ends withthe letter "r"
zmey [24]

Answer:

Sulphur

Explanation:

Sulphur(S) is the Sixteenth element of the periodic table and it has an electronic configuration of 2,8,6. This means it has six electrons in its outermost shell( valence electrons).

Sulphur has sixteen(16) protons which is equal to the atomic number which is also sixteen. Sulphur ends with the letter ‘r’. All the descriptions of the element are satisfied and it validates Sulphur.

4 0
3 years ago
What is the formula ofchromium(III) hydrogensulfate?
FromTheMoon [43]

Answer:

Cr (HSO4)3

Explanation:

its molecular weight is 343.20 g/mol

its molecular formula can also be written as CrH3O12S3

molar mass of Cr (HSO4)3 can be calculated by following method;

atomic mass of Cr = 51.9961 u

atomic mass of H = 1 u

atomic mass of S = 32.065 u

atomic mass of O = 16 u

molar mass of Cr(HSO4)3 =  51.9961+ 1.00784×3 + 32.065×3 + 15.999×12

molar mass of Cr(HSO4)3 =51.9961+3.02352+96.195+ 191.988

molar mass of Cr(HSO4)3 = 343.20 g/mol

3 0
3 years ago
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