20. At STP, an element that is a solid and a
good conductor of heat and electricity
could have an electron configuration of
(1) 2-7
(2) 2-8-8
(3) 2-8-5
(4) 2-8-18-2
20

Answer:

Scientific models are not a replacement for experimentation. They can be used in conjunction with experimentation to further understanding of a concept, event, or process. They are based on current scientific knowledge and may have to be changed when new discoveries are made.

Explanation:

that's my answer

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Answer:

C

Explanation:

Edge 2022 trust the process

Knowing about the greenhouse effect we have that what intensifies this effect is an increase in gases in the atmosphere that absorb heat.

Greenhouse effect is a natural atmospheric phenomenon responsible for the maintenance of life on Earth. Without the presence of this phenomenon, the temperature on Earth would be very low, around -18ºC, which would make the development of living beings impossible.

Thus, the main cause of the greenhouse effect is industrialization. Due to this process, the burning of fossil fuels has intensified in recent centuries. The main products of the combustion reaction of these reagents are the gases mentioned above as the main ones for the greenhouse effect.

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Answer:

True

Explanation:

Volcanic eruptions and meteorite impacts were way more common back when the Earth was newly formed.

Answer:

at 39m

Explanation:

because thats where gravitational potential energy has been acting on it the most before it hits the ground.

pretty sure btw

Answer:

A) 17.5%

B) 1) 2135 kg

2) 375 kg

C) 91.8

Explanation:

Part (A):

1 tonne= 1000 kg= 100%

Aluminium oxide= 825 kg= 82.5%

Iron (lll) oxide= 100 kg= 10%

Sand= 85 kg= 7.5%

That makes total of 100%

So, the percentage of impurities= Iron (lll) oxide + Sand

=> 10 + 7.5= 17.5%

Part (B):

(1) 1 tonne= 427 kg

Multiplying both sides by 5

=> 5 tonne= 427 * 5

=> 5 tonne = 2135 kg

(2) 1 tonne contains 75 kg sand as impurity

=> 1 tonne= 75 kg

Multiplying both sides by 5

=> 5 tonnes = 75 * 5

=> 5 tonnes = 375 kg

Part (C):

If all of the iron oxide was removed, then only aluminium and sand are left.

Aluminium = 825 kg

Sand= 74 kg

Total of them makes it:

=> 825 + 74 = 899

So,

% age of Aluminium= 825/899 * 100

% age of Aluminium= 0.918 * 100%

% age of Aluminium= 91.8%

Answer:

..

Explanation:

In a significantly acidic medium, even a soluble sulfide like sodium sulfide will not facilitate precipitation of Fe, Zn, Mn, Co and Ni as their sulfides.

B: heating the reaction

hope i could help :D

Given what we know, we can confirm that relative atomic mass is calculated by comparing the particles to the atomic mass of a carbon-12 atom.

Therefore, given its abundant nature and the fact that it has been extensively studied, we can confirm that a carbon 12 atom has exactly 6 protons and 6 neutrons, making it very stable and the standard to which other atoms are compared.

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Answer:

Reduction

Explanation:

took the test

Answer: it definitely did help me a lot but sometimes it doesn’t make me happy like i will get stressed but it passes.

Explanation:

Based on N:Z ratio, Zr-85 is expected to decay by positron emission. Zr-95 is expected to emit beta particles in a beta decay.

The N:Z ratio determines the stability of a nucleus. If a nucleus has  N:Z ratio >1.5 or <1.0, such a nucleus is unstable and will undergo radioactive decay. The aim of such a decay is to attain a favorable  N:Z ratio.

For Zr -85, the  N:Z ratio is 1.1 while the  N:Z ratio of Zr-95 is 1.4.  Zr -85 is expected to decay by positron emission which increases the N:Z ratio. For  Zr-95, the nucleus tends to undergo processes that decrease the  N:Z ratio such as beta emission.

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Answer:

the ability to be dissolved, especially in water.

Explanation:

Answer:

1. Forward and Backward reaction rate are equal

2. Concentration of reactants and products are the same.

Answer:

chemical change

Explanation:

because chemical chande is a permanent change

Let's check Electronic configuration of N in ground state

[tex]\\ \sf\longmapsto 1s^22s^22p^3[/tex]

[tex]\\ \sf\longmapsto 1s^22s^22px^12py^12pz^2[/tex]

In hydrogen case

[tex]\\ \sf\longmapsto 1s^1[/tex]

Hence Hybridization

[tex]\\ \sf\longmapsto s-p-p-p[/tex]

[tex]\\ \sf\longmapsto sp^3[/tex]

Structure is tetrahedral .

Spare way:-

Hybridization

[tex]\\ \sf\longmapsto \dfrac{1}{2}[\sigma+\sigma *][/tex]

[tex]\\ \sf\longmapsto \dfrac{1}{2}[6+2][/tex]

[tex]\\ \sf\longmapsto \dfrac{1}{2}[8][/tex]

[tex]\\ \sf\longmapsto 4[/tex]

Answer:

The outer-shell similarity of the two elements suggests that arsenic, like phosphorus, can form three covalent bonds per atom, with an additional lone pair of electrons left unbonded.

Atomic number: 96

Oxidation states: +3, +4

Arsenic atom can form either three or five bonds in arsenic compounds.

In conclusion, arsenic is an element that could form three or five bonds in its compounds.

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Answer: The amount of CO2 found in the atmosphere varies over the course of a year. Much of this variation happens because of the role of plants in the carbon cycle

Answer:

first identify the cation and write down its symbol and charge. Then, identify the anion and write down its symbol and charge.

Explanation:

Answer:

If a solute is a solid or liquid, increasing the temperature increases its solubility. For example, more sugar can dissolve in hot water than in cold water. If a solute is a gas, increasing the temperature decreases its solubility. For example, less carbon dioxide can dissolve in warm water than in cold water.

Explanation:

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The balanced chemical equation for given reaction is ~

Answer:

No, mode isnt the middle value of a set that is median.

Explanation:

Mode (also known as modal class) is the value that appears most frequently in a data set.

Answer:

Explanation:

Oxidation reaction

The kind of reaction involving the transfer of electrons or hydrogen away from a molecule is called oxidation.

In the same vein, the molecule that receives the electron or the hydrogen atom is said to be reduced. This means that oxidation cannot exist in isolation without reduction.

In other words, oxidation is defined as:

While reduction is defined as:

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Answer:

8

EXPLANATION hope this helps you

Answer:8

Explanation:

Answer:

Explanation:

3