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Answer:

B

Explanation:

the reaction is endothermic because of the temperature drop and the enthralpy is negative because its an endothermic reaction.

I did some research so I believe this to be correct but if its no I'm sorry

Answer:

There are 6.022×1023 molecules in a mole. There are 18.01528 grams of water per mole of water. in 1g water

Explanation:

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Answer:humans have put ridiculous amounts of carbon dioxide into the atmosphereThese events are linked to the mass burning of fossil fuels to meet an increase in human demand

So the answer is True

Explanation:

Burning fossil fuels, such as coal and oil, has increased the quantity of greenhouse gases in our atmosphere since the Industrial Revolution began around 1750.

Atmosphere is defined as a layer of gas that surrounds a planet and is kept there by the gravitational pull of the planetary body. The atmosphere of Earth includes five primary layers and a number of minor ones.

Industrial revolution is defined as the transition of an economy based on agriculture and handicrafts to one driven by industry and machine production. The causes of industrial revolution are the advent of capitalism, European imperialism, efforts to mine coal, and the effects of the Agricultural Revolution are some of the factors that historians have recognized as contributing to the Industrial Revolution.

Thus, burning fossil fuels, such as coal and oil, has increased the quantity of greenhouse gases in our atmosphere since the Industrial Revolution began around 1750.

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Answer:

this girl in my class is getting a dog

Explanation:

but shes annoying so im hit her

Answer:

A positively or negatively charged particle is called an ion.

Explanation:

Ions form when they lose or gain electrons in order to become stable by filling their octet. When an element lose an electron(s), it becomes positively charged and occpanies the symbol (+). When an element gains an electron(s), it becomes negatively charged and occpanies the symbol (-).

Answer:

The Bohr Model is a planetary model in which the negatively-charged electrons orbit a small, positively-charged nucleus similar to the planets orbiting the Sun (except that the orbits are not planar). The gravitational force of the solar system is mathematically akin to the Coulomb (electrical) force between the positively-charged nucleus and the negatively-charged electrons.

Main Points of the Bohr Model

Electrons orbit the nucleus in orbits that have a set size and energy.

The energy of the orbit is related to its size. The lowest energy is found in the smallest orbit.

Radiation is absorbed or emitted when an electron moves from one orbit to another.

Have a great day friend! :D

A small positive charges nucleus is encircled by revolving negatively charged electrons in fixed orbits, according to the Bohr Atomic model.

The atom is basically depicted in the Bohr model as a central nucleus containing protons along with neutrons, with electrons in circular orbitals at various distances from the nucleus.

These orbits combine to form electron shells or energy levels, which allow you to see how many electrons are in each shell.

He concluded that electrons have more energy when they are located away from the nucleus, whereas electrons have less energy when they are located near the nucleus.

He was unable to explain the specifics of the Hydrogen and Helium atomic spectrums.

He did not explain how spectral lines split in the presence of a magnetic field. He did not explain the intensity of spectral lines.

Thus, these can be concluded regarding the Bohor's atomic model.

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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:

Octane

Octane is a straight chain alkane composed of 8 carbon atoms.

Answer:

GRAPHENE is a single layer of graphite

Explanation:

each carbon atom bonded to 3 other carbon atoms forming a hexagonal lattice

Answer:

Chemical formula: HNO₃

Melting point: −42 °C (−44 °F; 231 K)

Molar mass: 63.012 g·mol−1

Solubility in water: Miscible

Explanation:

When Conc HNO3 acid leaks into seawater presumed to be largely consisting of Sodium Chloride and other dissolved salts, I won't consider it as a chemical reaction rather it is a Physical Change. I presume this activity as a mixture when the acid been the solute becomes a contaminants

Answer:

Explanation:

3

Answer:

We can mix two compounds and create a third that bears little resemblance to its parents. For instance, by mixing two parts of hydrogen gas with one of oxygen - liquid water is formed. We should not be misled by the fact that chlorine and chlorine dioxide share a word in common. The chemistries of the two compounds are completely different.

Chlorine and chlorine dioxide are both oxidizing agents (electron receivers). However, chlorine has the capacity to take in two electrons, whereas chlorine dioxide can absorb five. This means that mole for mole, ClO2 is 2.6 times more effective than chlorine.

If equal, if not greater importance is the fact that chlorine dioxide will not react with many organic compounds, and as a result, ClO2 does not produce environmentally dangerous chlorinated organics. For example; aromatic compounds have carbon atoms arranged in rings and they may have other atoms, such as chlorine, attached to these rings, to form a chlorinated aromatic - a highly toxic compound that persists in the environment long after it is produced.  

Chlorine dioxide's behaviour as an oxidizing agent is quite dissimilar. Like ozone, the predominant oxidation reaction mechanism for chlorine dioxide proceeds through a process known as free radical electrophilic (i.e. electron-attracting) abstraction rather than by oxidative substitution or addition (as in chlorinating agents such as chlorine or hypochlorite). This means that chlorinated organic compounds such as THMs and HAAs are not produced as a result of disinfection using chlorine dioxide

Hope this helps, have a nice day! :D

The way that the names of these compounds show that the Chlorine oxides are different is by making reference to the number of individual molecules in the compound.

The number of chlorine and oxygen molecules in each compound are used to name the compounds which ensures that they are differentiated.

ClO₂ is called "Chlorine Dioxide" which shows that there are two Oxygen atoms.

Cl₂O₃ is called "Dichlorine Trioxide" which shows that there are two Chlorine molecules and 3 Oxygen molecules.

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Answer:

1.22gram of hydrogen is needed to react

Mole measure the number of elementary entities of a given substance that are present in a given sample. Therefore,  0.40 g mass of hydrogen is needed to react with 32 g of copper oxide.

The SI unit of amount of substance in chemistry is mole. The mole is used to measure the quantity or amount of substance. We know one mole of any element contains 6.022×10²³ atoms which is also called Avogadro number.

Mathematically,

CuO + H[tex]_2[/tex]→ Cu + H[tex]_2[/tex]O

mole of copper oxide=  32 /79.54

                                    =0.40 mole

The mole ratio between copper oxide and hydrogen is 1:1

mole of hydrogen= 0.40 mole

mass of hydrogen = 0.40 mole×1g/mol

                              = 0.40 g

Therefore, 0.40 g mass of hydrogen is needed to react with 32 g of copper oxide.

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Answer:0.2865

Explanation:

Answer:

But when there is too much phosphorus and nitrogen into water systems, it can speed up the process of eutrophication ( increase in the concentration of minerals and nutrients, which enhances the growth of algae, which causes algal blooms). Due to this, dissolved oxygen level is declined as not enough light penetrates in the water body.

Explanation:

Answer:

its true..plz mark me brainliest

Explanation:

Answer:The number of BH+ Molecules will increase , and the number of water molecules will decrease

Explanation:

The number of OH- ions will increase, and the number of BH molecules will decrease.

Option (3) is correct.

In the given base solution equation, B + H₂O = BH⁺ + OH⁻, when the strength of the base is increased, more B molecules will react with water to form BH⁺ and OH⁻ ions. This happens because a stronger base donates more OH⁻ ions into the solution, increasing its concentration.

As the base becomes stronger, more B molecules will participate in the reaction, forming fewer BH⁺ molecules since they are being converted to BH⁺ ions. Simultaneously, the increased concentration of OH⁻ ions means that the number of OH⁻ ions in the solution will increase.

Overall, the change in the number of particles can be summarized as follows:

The number of BH molecules will decrease.

The number of OH⁻ ions will increase.

This change reflects the increase in the concentration of OH⁻ ions, which is a characteristic of a stronger base solution.

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Answer: The four forces acting on an aircraft in straight-and-level, unaccelerated flight are thrust, drag, lift, and weight.

Explanation:

Answer:

J.J. Thomson's experiments with cathode-ray tubes showed that all atoms contain tiny negatively charged subatomic particles or electrons. Rutherford's gold foil experiment showed that the atom is mostly empty space with a tiny, dense, positively-charged nucleus. I would describe the structure of an atom as the plum pudding model.

Answer: You have to have good mechanics as well as the curve with velocity and speed.

The MLB Pitchers you see can be an example.

Commentators yelling Nasty Curveball, Strikeout!!

Answer:

4

Explanation:

Zinc

1. The energy associated with an electromagnetic radiation of [tex]6.34 \times 10^{15} \;Hertz[/tex] is equal to [tex]4.2 \times 10^{-18}\;Joules[/tex].

2. The frequency of one of the bands of the sodium emission spectrum is [tex]5.13 \times 10^{14}\;Hertz[/tex]

Given the following data:

Scientific data:

1. To determine the energy associated with an electromagnetic radiation of [tex]6.34 \times 10^{15} \;Hertz[/tex], we would apply Einstein's equation for photon energy:

Mathematically, Einstein's equation for photon energy is given by the formula:

[tex]E =hf[/tex]

Where:

Substituting the given parameters into the formula, we have;

[tex]E = 6.626 \times 10^{-34}\times 6.34 \times 10^{15} \\\\E = 4.2 \times 10^{-18}\;Joules[/tex]

2. To determine the frequency of one of the bands of the sodium emission spectrum:

Mathematically, the frequency of a wave is given by the formula:

[tex]Frequency = \frac{Speed}{wavelength} \\\\Frequency = \frac{3 \times 10^8}{5.85 \times 10^{-7}} \\\\Frequency =5.13 \times 10^{14}\;Hertz[/tex]

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Answer:

science of electromagnetic fields

Explanation:

(winks and runs off)

The molecular mass (molar mass) of this gas is equal to 44.08 g/mol.

Given the following data:

To calculate the molecular mass (molar mass) of this gas, we would use the ideal gas law equation;

[tex]PV=\frac{MRT}{MM}[/tex]

Where;

Making MM the subject of formula, we have:

[tex]MM = \frac{MRT}{PV} \\\\MM = \frac{23.6\times 0.0821 \times 273}{1 \times 12}\\\\MM = \frac{528.95}{12}[/tex]

Molar mass, MM = 44.08 g/mol.

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Answer:

6 possible electron can fit into the 2p subshell

Answer:

Acid + Base -------> Salt + Water

Explanation:

The reaction between an acid and bases is called a neutralization reaction. The result of the reaction is salt and water. For example, when hydrochloric acid(acid) and sodium hydroxide(base) react they form sodium chloride(salt) and water. Also, heat is evolved.

Example:

HCl + NaOH ----------> NaCl + H2O

HCl is hydrochloric acid.

NaOH is sodium hydroxide which is a base.

NaCl is sodium chloride which is a salt.

H2O is water.