The diagram shows the box for elements in the periodic table. What is the atomic number of the element shown. A. 27.0 B. 40.0 C.26 D.13

I think it is B.40.0
Because if you do 27+13=40
It will give 0.

Answer:

The answer is B

B = Petri dishes and sterile droppers

Explanation:

There are two modes in which unstable nuclei of radioactive elements may decay. They are by α - emission or by β - emission. Among the given options, the α - emission is ₆₄¹⁴⁸Gd → ₆₂¹⁴⁴Sm + ₂⁴He. The correct option is D.

According to the theory of radioactive disintegration, the atoms of all the radioactive elements undergo spontaneous disintegration with the emission of α or β particles to yield atoms of new elements. When a radionuclide decays by emitting an  α - particle, it is called α - decay.

When a radionuclide undergoes  α - emission, i.e. a helium nucleus there occurs a decrease of 2 units in the atomic number and a decrease of 4 units in the mass number. The new nuclide produced has an atomic number 2 units less and a mass number 4 units less than the parent.

₆₄¹⁴⁸Gd → ₆₂¹⁴⁴Sm + ₂⁴He represents α - emission.

Thus the correct option is D.

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Answer:

It is the one that has start and finish and a compass on it...I am sorry I can share images for some reason. And underneath the compass, it says 1.0 Mile. It also has a compass in the bottom right-hand corner.

Explanation:

I just took the quiz and got it correct!

Considering the reaction stoichiometry, the enthalpy change if enough propane was burned to give off 12 moles of carbon dioxide gas is 8228 kJ.

The balanced reaction is:

C₃H₈(g) + 5 O₂(g) → 3 CO₂(g) + 4 H₂O(l)

The heat of combustion of propane, C₃H₈, is -2057 kJ/mol. This is, 2057 kJ is released for every 1 mol C₃H₈.

So to determine the enthalpy change if enough propane was burned to emit 12 moles of carbon dioxide, you must take into account the stoichiometry of the reaction.

By reaction stoichiometry (that is, the relationship between the amount of reagents and products in a chemical reaction), the following amounts of moles of each compound participate in the reaction:

Then you can apply the following rule of three: if by stoichiometry 3 moles of CO₂ are produced by 1 mole of C₃H₈, 12 moles of CO₂ are produced by how many moles of C₃H₈?

[tex]amount of moles of C_{3} H_{8} =\frac{12 moles of CO_{2}x1 mole of C_{3} H_{8} }{3 moles of CO_{2}}[/tex]

amount of moles of C₃H₈= 4 moles

So to determine the enthalpy change, you can apply the following rule of three: If for each mole of C₃H₈ 2057 kJ are released, for 4 moles of C₃H₈ how much heat is released?

[tex]Heat released=\frac{4 molesx2057 kJ}{1 mole}[/tex]

Heat released= 8228 kJ

The enthalpy change if enough propane was burned to give off 12 moles of carbon dioxide gas is 8228 kJ.

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Answer:

There are 95 atoms in mercury phosphate

Explanation:

You just add the atomic number for both elements

Answer:

C

Explanation:

The azimuthal quantum number can take values from 0 to (n-1)

So in answer C n= 3, l can take values between 0

and 2.

l can't be 3.

ml can take values from -l to +l.

Hope you understood

Experiment: Does it Dissolve?

Materials Needed:

Step 1: Form a question before starting the experiment.

Step 2: Make a hypothesis for each substance.

Step 3: Scoop a teaspoon of each substance in the jars, only adding one substance per jar. Stir it up!

Step 4: Observe whether or not each substance dissolves and record the findings.

As far as the intelligence of canines, it is widely accepted as a fact that the Border Collie is the most intelligent breed of dog.

The conclusion that border collies are the most intelligent breed of dog is credited to a canine psychologist by the name of Stanley Coren. He studied over 138 recognized breeds of dogs to measure the ease with which they learned new commands and the obedience rate of each breed.

Coren studies the learning and obedience of Border Collies over the course of 199 trials and found that this breed of dog performed 95% better than most other breeds, with only 9 of the 138 breeds studied coming close to the results of the border collie. Easily earning the title of the most intelligent breed of dogs.

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Answer:

When the base neutralizes the acid, the number of moles of H+ = the number of moles of OH-. Therefore, the number of moles of H+ = 0.0125 moles. Every mole of HCl will produce one mole of H+; therefore, the number of moles of HCl = number of moles of H+. The concentration of the HCl is 0.25 M

Answer: 1 mole

Explanation:

One mole reacts because there is a 1:1 ratio between the potassium and water at the beginning of the equation. 2K+2H2O has a 1 to 1 ratio. If one potassium reacts there is one h2o that also reacts.

Taking into account the reaction stoichiometry, if one mole of potassium reacts, 1 mole of water are consumed.

In first place, the balanced reaction is:

2 K + 2 H₂O → 2 KOH + H₂

By reaction stoichiometry (that is, the relationship between the amount of reagents and products in a chemical reaction), the following amounts of moles of each compound participate in the reaction:

The amount of water consumed is calculated from the following rule of three: if by stoichiometry 2 moles of K react with 2 moles of H₂O, 1 mole of K react with how many moles of H₂O?

[tex]amount of moles of H_{2} O=\frac{1 mole of Kx2 moles ofH_{2} O }{2 moles of K}[/tex]

amount of moles of H₂O= 1 mole

In summary, if one mole of potassium reacts, 1 mole of water are consumed.

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Answer:

Specific heat of ethyl chloride in gas and liquid phases, enthalpy of vaporization and specific heat of solid surface.

Explanation:

In order to determine the final temperature, the heat lost by the chloride needs to be found. This would require the specific heat in both phases and the enthalpy of vaporization. (you will use q=mc(delta)T and q=m(delta)H)

Then the energy gained by the surface needs to be found. This will require the specific heat in order to use the q=mc(delta)T equation.

The enthalpies that we consider to calculate the final temperature of the surface are Specific heat of surface and ethyl chloride as well as Heat of vaporization of liquid & vapor ethyl chloride.

Enthalpy of any reaction tells about the total amount of heat absrobed and released during a chemical reaction.

According to the question, heat released by the surface is absorbed by the ethyl chloride and by absorbing this energy ethyl chlorode will change into the vapor form. In the whole process if we want ot calculate the final temperature on the surface then we should consider:

Hence, required enthalpies are Specific heat of surface and ethyl chloride as well as Heat of vaporization of liquid & vapor ethyl chloride.

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Answer:

3. 0.819L (819 mL)

Explanation: Before we go about solving this, we need to do some conversions prior to using the gas law, the gas law is as follows...

P(atm)*V(L)=n(mol)*r(constant)*T(in kelvin)

So here are all the conversions you need.

620 mm Hg -> 0.816 atm

1140 mL -> 1.14 L

37 C -> 310.15 K

After plugging in our new converted values, we will proceed to solve the number of moles of the gas present, our n value, so our equation will look like this...(Note: Constant r in this case is 0.08206 L*atm/K*mol)

(0.816 atm)(1.14 L) = n(0.08206)(310.15)

Solving for n we get 0.03653 moles.

Now our second part is to figure out the volume AT STP (standard temperature/pressure). In the STP conditions, your temperature defaults to 0 C (273.15 K) and 1 atm. Now there is an easier way to do this, but I'll also show the more comprehensive way. Here is the easier method...

Since 1 mole of every gas occupies 22.4 L at STP, we can simply multiply this by our number of moles. So (22.4L)(0.3653 mol) to give us 0.818272.

However, a more accurate answer can be given like this...

Plugging n back into the same equation and this time resetting pressure to 1 atm and temperature to 273.15 K and conserving our number of moles we get...

(1 atm)(v) = (0.03653 mol)(0.08206)(273.15 K)

v = (0.03653)(0.08206)(273.15)

v = 0.8188 L = 0.819 L or 819 mL

Answer:

The dipole forces (particularly H-bonds) that keep polar solute molecules together can be replaced by polar solute-solvent interactions, so substances that are predominantly polar (like glucose) dissolve in polar solvents like water but not in nonpolar solvents like hexane (H-bonds).

Explanation:

Answer:

you see le bear

you brain sends signals

your heart and lungs receive said signals

spring to action

no I will not please put you because that's the god of the Bible

Metals are good conductors of heat and electricity, and are malleable (they can be hammered into sheets) and ductile (they can be drawn into wire).

Nonmetals are (usually) poor conductors of heat and electricity, and are not malleable or ductile; many of the elemental nonmetals are gases at room temperature, while others are liquids and others are solids. 

The metalloids are intermediate in their properties.  In their physical properties, they are more like the nonmetals, but under certain circumstances, several of them can be made to conduct electricity.

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Answer:

Every amino acid also has another atom or group of atoms bonded to the central atom known as the R group. This R group, or side chain, gives each amino acid proteins specific characteristics, including size, polarity, and pH.

Explanation:

The R group is another atom or group of atoms that is attached to the core atom in every amino acid. This R group, or side chain, provides each amino acid protein with unique properties such as size, polarity, and pH.

Amino acids are chemical molecules that are used to construct proteins. Proteins are vital macromolecules in living organisms, serving a variety of functions including enzymatic catalysis, structural support, transportation, immunological response, and others. A polypeptide chain is formed by linking amino acids in a precise sequence, which subsequently folds into a three-dimensional structure to make a functioning protein.

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Answer:

Use the Rydberg Equation 1/λ = R(1/n²(final) - 1/n²(initial) where R = 109,678 cm⁻¹. Substitute initial orbital number and final orbital number and solve for wavelength (λ).

Explanation:

Example:

Assume an electron transition from n = 5 to n = 2.

1/λ = 109,678cm⁻¹(1/2² - 1/5²) = 109,678(0.25 - 0.04)cm⁻¹ = 23,032cm⁻¹

λ = 1/23,032cm⁻¹ = 4.34 x 10⁻⁵cm x 10⁻²m/cm x 10⁹nm/m = 434nm

Answer -ˋˏ ༻༺ ˎˊ-

A common use for gravity filtration is for separating anhydrous magnesium sulfate (MgSO4) from an organic solution that it has dried (Figure 1.68b). Anhydrous magnesium sulfate is powdery, and with swirling in an organic solvent creates a fine dispersal of particles like a snow globe.

Answer:

C. Both depend on how much matter an object has.

Explanation:

weight is the gravitational force acting on an object, so it does vary depending on gravity.

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Thank You

Explanation:

A moon orbits in a roughly circular path around a planet with a mass of 8.6 x 1023 kg. The distance from the center of the moon to the center of the planet is 7.04 x 106 meters. Calculate the speed of the moon in m/s.

Answer:

James Chadwick conducted an experiment where he assailed the element Beryllium with alpha particles that came from the radioactive decay of Polunium. The experiment results showed highly penetrating radiation emitted from the Beryllium. In this, Chadwick proposed that radiation consisted of uncharged particles, which were later founded as neutrons.

Answer:

[tex]\boxed {\boxed {\sf 353 \ mL}}[/tex]

Explanation:

We are asked to find the volume in milliliters of a solution, given the mass of solute and molarity of the solution.

Molarity is a measure of concentration in moles per liter.

[tex]molarity = \frac {moles \ of \ solute}{liters \ of \ solution}[/tex]

We are given the mass of the solute. We must convert the mass to moles using the molar mass (the mass of 1 mole of a substance). These values are found on the Periodic Table. They are equal to the atomic masses, but the units are grams per mole instead of atomic mass units.

Look up the molar masses of the individual elements in calcium chloride.

The chemical formula, CaCl₂, has a subscript of 2. There are 2 moles of chlorine in 1 mole of calcium chloride. We must multiply chlorine's molar mass by 2 before adding calcium's molar mass.

Set up a conversion factor using the molar mass.

[tex]\frac {110.98 \ g \ CaCl_2}{1 \ mol \ CaCl_2}[/tex]

Multiply by 45.0 grams of calcium chloride.

[tex]45.0 \ g \ CaCl_2 *\frac {110.98 \ g \ CaCl_2}{1 \ mol \ CaCl_2}[/tex]

Flip the conversion factor so the units of grams of calcium chloride cancel.

[tex]45.0 \ g \ CaCl_2 *\frac{1 \ mol \ CaCl_2} {110.98 \ g \ CaCl_2}[/tex]

[tex]45.0 \ *\frac{1 \ mol \ CaCl_2} {110.98}[/tex]

[tex]\frac {45.0}{110.98} \ mol \ CaCl_2= 0.405478465 \ mol \ CaCl_2[/tex]

Now we can find the liters of solution.

[tex]molarity = \frac {moles \ of \ solute}{liters \ of \ solution}[/tex]

Substitute the values into the formula.

[tex]1.15 \ mol \ CaCl_2/L = \frac{0.405478465 \ mol \ CaCl_2}{x}[/tex]

Cross multiply.

[tex]\frac {1.15 \ mol \ CaCl_2 /L}{1}= \frac{0.405478465 \ mol \ CaCl_2}{x}[/tex]

[tex]{1.15 \ mol \ CaCl_2 /L}*x= {0.405478465 \ mol \ CaCl_2} * 1[/tex]

Divide both sides of the equation by 1.15 moles of calcium chloride to isolate the variable x.

[tex]\frac {1.15 \ mol \ CaCl_2/L *x}{1.15 \ mol \ CaCl_2 /L}= \frac{0.405478465 \ mol \ CaCl_2 * 1 }{1.15 \ mol \ CaCl_2/L }[/tex]

[tex]x=\frac{0.405478465 \ mol \ CaCl_2 * 1 }{1.15 \ mol \ CaCl_2 /L}[/tex]

The units of moles of calcium chloride cancel.

[tex]x=\frac{0.405478465 }{1.15 \ L }[/tex]

[tex]x=0.35258997 \ L[/tex]

There are 1000 milliliters in 1 liter.

[tex]\frac {1000 \ mL}{1 \ L}[/tex]

[tex]0.35258997 \ L * \frac{1000 \ mL}{ 1 \ L}[/tex]

[tex]0.35258997 * 1000 \ mL=352.58997 \ mL[/tex]

The original measurements of mass and molarity have 3 significant figures, so our answer must have the same. For the number we found, that is the ones place. The 5 in the tenth place tells us to round the 2 up to a 3.

[tex]353 \ mL[/tex]

The volume of the solution is approximately 353 milliliters.

Answer:

The ironization energies increase as you go across the period So the electrical conductivity of the oxides is your answer

Answer:

Words are filled in

Eating a healthy breakfast gives your body the energy needed to help you start your day.. The girl in the photo is having cereal and orange jucie, both of which have stored chemical energy, a form of potential energy. The girls body breaks down the components of the food to access the energy in them. Later in the day, some of this energy is transformed into kinetic energy that will allow the girl to study and play sports. Some of this energy is also transformed into thermal energy that keeps her body warm.

Explanation:

Answer:

c

Explanation:

allow plants to absorb water and nutrients from the soil