When an atom is charged, it is called an ion. How many electrons are in O^2-?

Answer:

The first 5 are exothermic reaction because heat is in product means heat is evolved or given out.

And last no reaction shows that heat is required so last reaction is endothermic reaction.

Explanation:

And heat is evolved in exothermic reaction and heat is absorbed in endo thermic reaction

Answer:

Each sample has the same number of molecules.

Explanation:

Just took the quiz on edge 2021

Taking into account the definition of Avogadro's number, each sample has the same number of molecules.

Avogadro's Number or Avogadro's Constant is called the number of particles that make up a substance (usually atoms or molecules) and that can be found in the amount of one mole of said substance. Its value is 6.023×10²³ particles per mole.

Avogadro's number applies to any substance.

Avogadro's number applies to any substance. This means that the number of molecules in 1 mol of oxygen is equal to the number of molecules in 1 mol of nitrogen.

Finally, the correct answer is the third option: each sample has the same number of molecules.

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Answer:

The pan on the bottom right with the arrows pointing up.

Explanation:

conduction is the transfer of heat through touching surfaces, so when you place the pan on a hot stove, the heat heats up the bottom of the pan, and then the water in it.

The transfer of energy between systems through work is the expansion of gas in a steam engine. Therefore, the second diagram in the second row shows the correct direction of flow of heat.

Energy transfer is a phenomenon in which energy transfer from one matter to another matter. Energy can be transferred in two forms that are by doing work or by transferring heat.

Heat can be transferred by three ways conduction, convention and radiation. In conduction, when two object are in direct contact, transfer of molecules takes place. When heat flow through touching surfaces is called conduction. Heat flows in the upward direction from bottom in a pan.

Therefore, the second diagram in the second row shows the correct direction of flow of heat.

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Explanation:

There is a limit to different things we encounter around the universe due to a lot of reasons.

To overcome these barriers, some catalysts that are not readily available are needed. This reduces the combination of some atoms in nature.

This and many more reasons limits the combination of chemical substances.

There is a limit to different things we encounter around the universe due to a lot of reasons:

So, for a chemical reaction to occur there are certain parameters that need to taken into consideration for a chemical reaction to actually takes place.

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Answer:

Viscosity

Explanation:

Viscosity is how thick a liquid is due to internal friction.

Answer:

Manganese

Explanation:

The electronic configuration of the atom is:

         1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d⁵

The powers in this configuration is the number of electrons in each orbital:

2 + 2 + 6 + 2 + 6 + 2 + 5  = 25

The compound has 25 electrons and it is Manganese

The electron configuration 1s22s22p63s23p64s23d5 corresponds to the element manganese (Mn).

In the electron configuration provided:

1s2 represents the filling of the 1s subshell with two electrons.

2s2 represents the filling of the 2s subshell with two electrons.

2p6 represents the filling of the 2p subshell with six electrons.

3s2 represents the filling of the 3s subshell with two electrons.

3p6 represents the filling of the 3p subshell with six electrons.

4s2 represents the filling of the 4s subshell with two electrons.

3d5 represents the filling of the 3d subshell with five electrons.

Based on this electron configuration, we can correctly identify the element as manganese (Mn), which has an atomic number of 25.

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Answer:

Its has a lower density. Think about it, a ship in the water is long because if it wasn't it would have a higher density and sink. The ship needs to diperse its weight across the water to make it less dense.

Explanation:

Your welcome! Have a great day!

Answer:

Liquids

Explanation:because animals like dolphins use sound radiation under water to hear each other

Answer:

D. all of these.

Explanation:

it can travel through solids, liquids, and gasses.

Answer:

Explanation:

People use detector to know the ionization of electromagnetic radiation i.e alpha, beta and gamma radiation and the output produced.

In the past, the early detectors use photographic plates which is use to detect tracks due to nuclear reactions.

It is important to know particles before inventing detectors because detectors produces visible trajectories or tracks as a result of particles that are charged which can traverse the apparatus. It was used to detect the positron and also muons and these w are particles that are produced by cosmic rays which is as a result of their interaction in the Earth's atmosphere.

Answer:

75 grams

Explanation:

At 95 °C, you can dissolve up to 75 grams of K2Cr2O7 in 100 mL of water.

The solubility of a substance in a particular solvent is the maximum amount of that substance that can dissolve in the solvent at a given temperature. The solubility of a substance can be affected by factors such as temperature, pressure, and the presence of other substances.

For K2Cr2O7, the solubility in water is highly dependent on temperature. At 95 °C, the solubility of K2Cr2O7 in water is approximately 75 g/100 mL. This means that at 95 °C, you can dissolve up to 75 grams of K2Cr2O7 in 100 mL of water. Since 100 g of water is equivalent to 100 mL, you can dissolve up to 75 grams of K2Cr2O7 in 100 g of water at 95 °C.

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Answer:

90 Minutes

Explanation:

Original concentration = 120 mg

Half life = 30 minutes

Minimum level = 15 mg

Basically, we are to calculate the time it would take to drop from 120 mg to 15 mg.

The half life of a substance is the time it takes for the original concentration of a substance to drop to half it's starting concentration.

First Half life:

Starting concentration = 120mg

Concentration after half life = 120 / 2 = 60 mg

Second Half life;

Starting concentration = 60 mg

Concentration after half life = 60 / 2 = 30 mg

Third Half life;

Starting concentration = 30 mg

Concentration after half life = 30 / 2 = 15 mg

We have reached the minimum 15 mg level. This means it took three half lives to get there.

Total time taken = No of Half lives * Half life duration = 3 * 30 mins = 90 Minutes

Answer:

Plasma.

Explanation:

In science, matter can be defined as anything that has mass and occupies space. Any physical object that is found on earth is typically composed of matter. Matter are known to be made up of atoms and as a result has the property of existing in states. The three (3) classical states of matter are;

I. Solid.

II. Liquid.

III. Gas

Plasma can be defined as a state of matter in which the electrons temporarily separate from the protons and as a result, it is generally referred to as the fourth (4th) state of matter due to its superheated nature.

Answer:

2 moles

Explanation:

1.9982182553889358 real number but round up to 2

320 g IF₇

Math

Pre-Algebra

Order of Operations: BPEMDAS

Chemistry

Atomic Structure

Step 1: Define

7.3 × 10²³ molecules IF₇

Step 2: Identify Conversions

Avogadro's Number

Molar Mass of I - 126.90 g/mol

Molar Mass of F - 19.00 g/mol

Molar Mass of IF₇ - 126.90 + 7(19.00) = 259.9 g/mol

Step 3: Convert

Step 4: Check

Follow sig fig rules and round. We are given 2 sig figs.

315.056 g IF₇ ≈ 320 g IF₇

Answer: [tex]Hg_2^{2+}(aq)+2NO_3^-(aq)+2Na^+(aq)+2Cl^-(aq)\rightarrow Hg_2Cl_2(s)+2Na^+(aq)+2NO_3^-(aq)[/tex]

Explanation:

A double displacement reaction is one in which exchange of ions take place. The salts which are soluble in water are designated by symbol (aq) and those which are insoluble in water and remain in solid form are represented by (s) after their chemical formulas.  

A double displacement reaction in which one of the product is formed as a solid is called as precipitation reaction.  

The balanced chemical equation is:

[tex]Hg_2(NO_3)_2(aq)+2NaCl(aq)\rightarrow Hg_2Cl_2(s)+2NaNO_3(aq)[/tex]

The complete ionic equation will be :

[tex]Hg_2^{2+}(aq)+2NO_3^-(aq)+2Na^+(aq)+2Cl^-(aq)\rightarrow Hg_2Cl_2(s)+2Na^+(aq)+2NO_3^-(aq)[/tex]

Answer:

The unit for mass is the kilogram (Kg).

Explanation:

Hope this helped!! <3 good luckk!!

Answer:

11508 liters

Explanation:

The Faruq family uses 548 liters of water per day.  The Chammas family uses 3 times as much water  per day. How much water does the Chammas family use per week?

Solution:

The amount of water used by the Chammas family is three times that of the Faruq family per day, hence:

Amount of water used by Chammas family in a day = 3 * water used by Faruq family in a day

Amount of water used by Chammas family in a day = 3 * 548 = 1644 liters

The amount of water used by the Chammas family in a week = 1644 liters per day * 7 days in a week = 11508 liters

Therefore 11508 liters of water was used by the Chammas family in a week

Answer:

Percent yield = 99.6%

Theoretical yield = 25.5 g

Explanation:

Given data:

Mass of copper = 12.5 g

Mass of copper(II) chloride produced = 25.4 g

Theoretical yield = ?

Percent yield = ?

Solution:

Chemical equation:

Cu + Cl₂       →        CuCl₂

Number of moles of copper:

Number of moles = mass/molar mass

Number of moles = 12.5 g / 63.5 g/mol

Number of moles = 0.19 mol

Now we will compare the moles of copper and copper chloride.

                  Cu          :           CuCl₂

                     1           :               1

                  0.19        :           0.19

Mass of CuCl₂: Theoretical yield

Mass = number of moles × molar mass

Mass = 0.19 mol × 134.45 g/mol

Mass = 25.5 g

Percent yield:

Percent yield = (actual yield / theoretical yield )×100

Percent yield  = ( 25.4 g/ 25.5 g) ×100

Percent yield = 99.6%

Explanation:

1)

2Fe+3Cl2 →2FeCl3

2)

CH4+2O2 → CO2 +2H2O

3)

SnO2+2H2 →2H2O +Sn

4)

2KOH + H2SO4 → K2SO4+2H2O

Answer:

The moles present in 60 g of calcium are 1.5 moles.

Answer:

In 60 grams there are 1,5 mols

Explanation:

Answer:

a. HF

Explanation:

Answer:

Mass = 15.12 g

Explanation:

Given data:

Mass of sodium borohydride = ?

Number of moles of sodium borohydride =0.40 mol

Solution:

Formula:

Mass = number of moles / molar mass

Molar mass of sodium borohydride = 37.8 g/mol

By putting values,

Mass = 0.40 mol × 37.8 g/mol

Mass = 15.12 g

Answer:

I think qs. "A" the net force acting on the book by gravity is down..

The statement is "The net force acting on the book by gravity is down."

Gravity is defined as the force that pulls materials toward the center point of a planet or other entity.

The textbook falls to the ground because of gravitational attraction between the ground and the book.

Because of the Earth's gravitational influence, the textbook moves towards the Earth when nothing is keeping it up. We know that the book has an equivalent impact on the Earth.

With a free fall acceleration of g, the textbook accelerates toward the Earth.

Hence, the correct option is A

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Answer:

A. Solid aluminum oxide and solid iron

Explanation:

The reaction equation is given as:

    2Al  +   Fe₂O₃  →   Al₂O₃   + 2Fe

The species on the left hand side are the reactants

Those on the right hand side of the expression are the products.

The products are:

Al₂O₃   and Fe

 These are solid aluminum oxide and solid iron

Answer:

NH₄NO₃

Explanation:

In salt naming, the cation is named first, then you must put the name of the anion. In the same way when you are writting the formula. Also, the global charge of a salt is always 0.

Thus, we must write each ion and its charge:

Ammonium: NH₄⁺

Nitrate: NO₃⁻

As both ions have the same charge, the formula is:

The cation first and then the anion.

Answer:

Household cleaners, antiseptics and battery juice are examples of toxic chemicals that you cannot consume because they have high acids concentrations. However some are very healthy such as critic acids found in oranges. :) Hope this helped.

Answer:

It is soft and white. It has a low melting and boiling point, a good conductor electricity, and reacts with water. Furthermore, it is also highly reactive, malleable, and ductile.

Explanation:

Hope I helped!

Answer:

silvery-white and waxy

Explanation:

Properties means the observations you can make just by looking at it or the qualities that the object has.

So when I looked at the sodium I saw a silvery-white metal (sodium is a metal), that has this waxy appearance to it.

Answer:

This compound is HNO2

Explanation:

HNO2 ----> H+ + NO2

When metals and non metals combine in fixed proportion then a chemical compound is formed So, the compound that will be formed from  hydrogen ion and nitrate ion is Hydrogen nitrate.

Chemical formula is a formula where cation and anion combine to form a molecule in fixed proportion. Metals combine in form of cation and non metals combine in form of anion.

Cation is the species that give electron and attain positive charge while anion is a species which gain electron and attains negative charge so when anion and cation combine in fixed ration the the overall charge of the molecule is zero that is molecule is neutral, the charge over cation and anion is also called oxidation state.

Therefore, the compound that will be formed from hydrogen ion and nitrate ion is Hydrogen nitrate.

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Answer: in the daytime the sun is out so the stars are not visible becuase the suns reflection! At night When you gaze at the constellations, every star produces an image that's the same size, but your retina isn't sensitive enough to respond to the outer parts of those images except for the brighter stars — which therefore look bigger than the fainter ones.

Explanation:

This is what I found on goog.le a while ago now it might actually help if I’m wrong I apologiz, I hope this was your quistion!