What is an element? Arrow

Answer:

[Xe] 6s2

Explanation:

hope it helps Electron configuration

The energy of the photon with a frequency of 9.50×10¹³ Hz is 6.29×10¯²⁰ J

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

Frequency (f) = 9.50×10¹³ Hz

Planck's constant (h) = 6.626×10¯³⁴ Js

The energy of the photon can be obtained as follow:

E = hf

E = 6.626×10¯³⁴ × 9.50×10¹³

Therefore, the energy of the photon is 6.29×10¯²⁰ J

Learn more: https://brainly.com/question/7957705

Answer:

nitrogen, oxygen and fluorine

The oxidation half equation is Zn ------> Zn^2+ + 2e while the reduction half equation is Cu^2+  + 2e------> Cu.

A redox reaction is a reaction in which there is a loss/gain of electrons. The specie that gives out electrons experiences an increase in oxidation number while the specie that gains the electrons experiences a decrease in oxidation number.

For the reaction; CuCl2 + Zn → ZnCl2 + Cu

The oxidation half equation is;

Zn ------> Zn^2+ + 2e

The reduction half equation is;

Cu^2+  + 2e------> Cu

The chloride ion is excluded because its oxidation number does not change from left to right in the reaction.

Learn more: https://brainly.com/question/967776

The theoretical yield of sodium chloride when 8.3 g of sodium react with 4.5 g of chlorine is 3.30 g

We'll begin calculating the masses of Na and Cl that reacted and the mass of NaCl produced from the balanced equation.

Molar mass of Na = 23 g/mol

Mass of Na from the balanced equation = 2 × 23 = 46 g

Molar mass of Cl₂ = 2 × 35.5 = 71 g/mol

Mass of Cl₂ from the balanced equation = 1 × 71 = 71 g

Molar mass of NaCl = 23 + 35.5 = 58.5 g/mol

Mass of NaCl from the balanced equation = 2 × 58.5 = 117 g

SUMMARY

From the balanced equation above,

46 g of Na reacted with 71 g of Cl₂ to produce 117 g of NaCl

From the balanced equation above,

46 g of Na reacted with 71 g of Cl₂

Therefore,

8.3 g of Na will react with = (8.3 × 71)/46 = 12.81 g of Cl₂

From the calculation made above, we can see that a higher amount (i.e 12.81 g) of Cl₂ than what was given (i.e 4.5 g) is needed to react completely with 8.3 g of Na.

Therefore, Cl₂ is the limiting reactant and Na is the excess reactant

From the balanced equation above,

71 g of Cl₂ reacted to produce 117 g of NaCl.

Therefore,

4.5 g of Cl₂ will react to produce = (4.5 × 117)/71 = 3.30 g of NaCl

Thus, the theoretical yield of NaCl produced is 3.30 g

Learn more: https://brainly.com/question/25669079

Answer:

The correct answer is 7.4 g NaCl

Explanation:

Answer:

see answer

Explanation:

DO the postulates of Daltons atomic theory explain the law of conservation of mass and the law of constant composition.

1. Everything is composed of atoms, which are the indivisible building blocks of matter and cannot be destroyed or divided any further.

2. All atoms of a single pure element are the same in size and mass

3. Atoms of different elements vary from each other in size and mass.

4. Compounds are produced through different simple whole-number combinations of atoms to produce molecules.  

5. Anywhere a compound exists, it will have the same atoms in the same ratio.

6. A chemical reaction between compounds is a re-arrangement of atoms

The law of conservation of mass is shown in 2, 4. and 5.

The law of constant co,position is shown in 2, 4, 5, and 6

Answer:

Q = mcT ...you can either substitute the molar heat capacity of water in the place of c or the specific heat capacity of water.

Explanation:

Answer:

you did not give the specific heat like formula like it takes 1kj to raise 28grams of water by 10 grams

Answer: Ne ( Neon )

Explanation: Lithium ( Li ), beryllium ( Be ), carbon ( C ), oxygen ( O ), and neon ( Ne ), are all in Period 2 in that order. Sodium ( Na ) is in Period 3. Since electron affinities decrease as you go down, Na would have a lower electron affinity level then Li but since electron affinities increase as you go across a period, only neon is farther right then oxygen ( O ), so it would be the only one element of this group that would have a higher electron affinity than that of oxygen.

There are various kind of elements that are present in periodic table. Some elements are harmful, some are radioactive, some are noble gases. Option C is correct option.

Periodic table is a table in which we find elements with properties like metals, non metals, metalloids and radioactive element arranges in increasing atomic number.

Periodic table help a scientist to know what are the different types of elements are present in periodic table so that they can discover the new elements that are not being discovered yet.

On going down the group electronegativity decreases. On going along the period the electronegativity increases. So, Neon lies on the extreme right of Fluorine in the same period. Neon will have more electronegativity than oxygen.

Therefore, Neon is more electronegativity than fluorine.

Learn more about periodic table, here:

https://brainly.com/question/11155928

#SPJ2

Answer: Place a piece of white paper under the analyte flask throughout the titration

Explanation:

The end point of titration can be made easy by the use of indicators. But we have to be keenly observe for each drop from the burette because, the colour change will be sudden for a drop.

Titration is an analytical technique used to determine the unknown concentration using a standard reagent of known concentration. The standard reagent of known concentration is called titrant and the  one to be determined is called analyte.

Usually analyte is taken in a conical flask and titrant in a burette. The end point of titration is the point at which the reaction is completed in perfect stoichiometry.

In acid-base titrations, the indicators used having different colors in different pH. Hence, the indicator in the analyte will change in color when the acidity of the medium changes. We have to observe keenly for the color change because it happens for any drop.

The adding of titrant from the burette must be dropwise and thus we can get a time to notice the sudden colour change of indicator.

To get more about titration indicators, refer the link below:

https://brainly.com/question/27419598

#SPJ5

Answer:

Cells are the basic structural unit of all living organisms.

Explanation:

Hope this helps, but i'm unsure if it would be multiple choice or not.

Answer:

c the answer is c that is the answer

Answer:

Calculating Atomic Mass

Change each percent abundance into decimal form by dividing by 100. Multiply this value by the atomic mass of that isotope. Add together for each isotope to get the average atomic mass.

Explanation:

have a nice day

In this exercise we want to calculate the amount of moles, so this is going to be:

[tex](4.6)(10^{-3}) \ mols \ CO_2[/tex]

Knowing that Henry's law is given by:

[tex]C = KHP[/tex]

Where constants are given by:

Before we can find the concentration of CO2 (and hence the moles of CO2), we first need to find its partial pressure.  We look up the vapor pressure of water at 25º and find it to be 0.03 atm.  Since the total pressure is equal to 0.1 atm, this mean the partial pressure of:

[tex]CO_2 = 0.1 \ atm - 0.03 \ atm = 0.07 \ atm[/tex]

Now using Henry's law, we find the concentration:

[tex]C = (0.033)*( 0.07) = (2.31)*(10^{-3})[/tex]

Converting to moles of CO2, we have:

[tex](2.31)*(10^{-3})*( 2) = (4.6)*(10^{-3})[/tex]

See more about concentration at https://brainly.com/question/3045247

The frequency of the infrared wave at the given speed and wavelength is [tex]5.5 \times 10^{13} \ Hz[/tex].

The given parameters;

The frequency of the infrared wave is calculated by using wave equation as shown below;

v = fλ

where;

[tex]f = \frac{v}{\lambda} \\\\f = \frac{3\times 10^8}{5.5 \times 10^{-6}} \\\\f = 5.5 \times 10^{13} \ Hz[/tex]

Thus, the frequency of the infrared wave at the given speed and wavelength is [tex]5.5 \times 10^{13} \ Hz[/tex].

Learn more here:https://brainly.com/question/18477700

Answer:

Test for carbon dioxide gas.

The reaction between baking soda and citric acid will form sodium ions, citric acid ions, carbon dioxide gas, and water. So all you have to do is add the gas produced (by gas displacement method or something) and test whether the gas is carbon dioxide, with lime water or other methods like hydrogencarbonate indicator. Hope this helped!

Explanation:

Answer:

depends on amount, but the reaction's endothermic (meaning its cold, absorbs heat from surroundings)

I hope it helps.

Answer:

ionic bond is the type of bond formed from electrostatic attraction between oppositely charged ion in a chemical compound

Answer:

sweat

Explanation:

you get dehydrated in hot weather because your body will release sweat to try and keep you cool

Answer:

Well, the heat can sometimes be very subtle in how it affects the body. If you're out in the sun, it can take just 30 minutes or up to a few hours for the heat to cause dehydration, nausea or it could cause trouble concentrating. When it's hot and humid, your risk of dehydration and heat illness increases. That's because when the air is humid, sweat can't evaporate and cool you as quickly as it normally does, and this can lead to an increased body temperature and the need for more fluids.

I HOPE DAT THIS HELPS :)

Explanation:

Actuating mechanism is the dry-chemical fixed application method which

introduces a concentration of agent into a closed area.

The actuating mechanism is commonly used in piping systems and

involves the transport of a control member in automatic or remote control

systems.

The closed system makes manual navigation very difficult which is why the

actuating mechanism in automatic systems are usually used to make it less

tedious and accurate.

Read more on https://brainly.com/question/19914723

Answer:

the charge or oxidation number on the cation and anion.

Explanation:

The factor that governs the formula of an ionic compound such as Ca3N2 is the charge or oxidation number on the cation and anion.

In the example, Ca has a +2 charge, N has a -3 charge

So we need 3 x ( +2) to balance 2 x (-3) and have an electrically neutral compound, so

+6 -6 =0

The factor that governs the formula of an ionic compound such as Ca₃N₂ is charge.

Those compounds in which ionic bond is present between the cation and anion is known as ionic compound.

The most important factor that is essential for the formation of ionic compounds are charge i.e. positive charge and negative charge. In the given compound Ca₃N₂, Calcium (Ca) is present in the +2 oxidation state and Nitrogen is present in the -3 oxidation state. So due to attraction between these charges they make a ionic compound.

Hence charge is important factor.

To know more about ionic compounds, visit the below link:

https://brainly.com/question/11638999

Answer:

I cannot tell yet

Explanation:

I don't take that class yet but ill get back to you

This problem is referring to an anhydrous salt that is derive from a hydrated Epson salt (magnesium sulfate hydrate) and the atom economy is required. However, not enough information is provided, yet we can use the attached file as a reference to provide a methodology of calculation.

To begin with, we need to calculate the [tex]x[/tex] which refers to the degree of hydration of the salt, so that we use the mass before and after heating the sample to figure out the grams and subsequently moles of water that are in there:

[tex]m_w=3.648g-1.782g=1.866g\\\\n_w=0.103molH_2O[/tex]

Next, since 1.782g corresponds to the anhydrous salt, we calculate the moles in such a amount:

[tex]1.782gMgSO_4*\frac{1molMgSO_4}{120.4gMgSO_4}=0.0148mol[/tex]

Then, we divide the moles of water by those of the anhydrous salt to calculte [tex]x[/tex]:

[tex]x=\frac{0.103mol}{0.0148mol} =6.96=7[/tex]

This means the formula of the hydrate is:

[tex]MgSO_4\ 7H_2O[/tex]

Finally, for the atom economy we just divide the molar mass of the anhydrous salt by that of the hydrate:

[tex]A.E=\frac{120.4g/mol}{246.47g/mol} *100\%\\\\A.E=48.8\%[/tex]

Learn more:

Explanation:

The burning of fossil fuels contributes to the addition of greenhouse gases to the atmosphere. These gases trap thermal energy in the Earth's atmosphere.

The materials which contain hydrocarbons which are generated from the remains of decay of plants and animals that are buried underground for many years are called fossil fuels.

The burning of fossil fuels can affect the environment, climatic conditions and human health. The burning of fossil fuels produces large amount of green house gases like CO₂, CH₄, etc. The increase in the amount of green house gases increases the heat and temperature of the earth's surface which leads to global warming.

The increase of temperature due to global warming can cause rise in the sea level, the glaciers of the earth will melt and coastal areas will be submerged under water due to this.

The burning of fossil fuels also releases toxic gases like SO₂, NO₂ which can cause acid rain and the emission these gases causes air pollution.

Thus the burning of fossil fuels has adverse effects.

To know more about fossil fuels, visit;

https://brainly.com/question/29770775

#SPJ6

Explanation:

after learning more about the position and would

Answer:

Nuclear fusion of hydrogen to form helium occurs naturally in the sun and other stars. It takes place only at extremely high temperatures. That's because a great deal of energy is needed to overcome the force of repulsion between the positively charged nuclei.

Explanation:

hope it helps

Answer:

b

Explanation:

Answer:

mark me brainlest

Explanation:

Electronegativity values generally increase from left to right across the periodic table. Electronegativities generally decrease from top to bottom of a group. The highest electronegativity value is for fluorine.

Answer:

       "Electronegativity increases as you move from left to right across a period because the number of charges on the nucleus increases." (sstudy30 on Quizlet)

Explanation:

    It explains itself haha!

Have a nice day!

    I hope this is what you are looking for, but if not - comment! I will edit and update my answer accordingly. (ノ^∇^)

- Heather

Answer:

In chemistry: a pure substance consists only of one element or one compound. a mixture consists of two or more different substances, not chemically joined together.

Hope this helps :)

Answer:

5.57 x 10^24 atoms

Explanation:

first, you are seeking the number of ATOMS of Boron.

Boron has an Atomic mass of 10.8 g/mol (see #5 on the periodic table)

100 gm of Boron would have 100 g /10.8 g/mol =9.26 moles

each mole has Avogadros number of atoms 6.02 x 10^23

9.26 moles has 9.26 x 6.02 x 10^23 atoms =5.57 x 10^24 atoms