Look at the picture below. Name the isotope

Calcium-19
Calcium-39
Potassium-20
Potassium-39

Answer:

1.58× 10²² atoms of Au

Explanation:

Given data:

Mass of gold = 5.18 g

Number of atoms of gold = ?

Solution:

First of all we will calculate the number of moles of gold.

Number of moles = mass/molar mass

Number of moles = 5.18 g/196.96 g/mol

Number of moles = 0.0263 mol

Number of atoms:

Avogadro number.

It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance.

The number 6.022 × 10²³ is called Avogadro number.

1 mole = 6.022 × 10²³ atoms of Au

0.0263 mol × 6.022 × 10²³ atoms of Au / 1mol

0.158× 10²³ atoms of Au

1.58× 10²² atoms of Au

Answer:

(C). Greater than 1atm

Explanation:

We are aware that water boils at 100 degree Celsius. Water can change its phase and become vapor at  100degree Celsius and at normal pressure which is 1atm.

In the given scenario we have enough temperature to convert water into vapor phase but we don't want it rather we want it to remain in liquid state. This can be achieved by increasing the pressure which was earlier required for vapor phase conversion. So the pressure should be greater than 1atm.

When we increase the temperature the molecules will get enough energy to escape into vapor phase, but when we will increase the pressure, it will provide hindrance to those molecules and will maintain them into Liquid state.

Answer:

K > Ca > Ge > Kr

Explanation:

The elements given are all in the 4th period on the periodic table.

       Kr, k, Ge, Ca;

Arranging their order from left to right;

         K, Ca, Ge, Kr

Atomic radius is taken as half the of the inter-nuclear distance (d) between two covalently bonded atoms of non-metallic elements or half the distance between two nuclei in the solid state of metals.

Across the periodic table atomic radii decreases progressively from left to right. This is due to progressive increase in the nuclear charge (number of protons in the nucleus) without an attendant increase in the number of electronic shells.

From the left to right; decreasing radii;

         K > Ca > Ge > Kr

Answer:

The center of the atom contains the nucleus so yes

Explanation:

Answer:

1. A. True

2. A. True

3. B. False

4. A. True

5. B. False

Explanation:

1. The particles are in constant motion. The collisions of the particles with the walls of the container are the cause of the pressure exerted by the gas. A. True. The pressure of an ideal gas is higher than the one that would exert a real gas.

2. The particles are assumed to exert no forces on each other; they are assumed neither to attract nor to repel each other. A. True. The intermolecular forces are negligible.

3. The particles are so small compared with the distances between them that the volume of the individual particles can be assumed to be about 1 mL. B. False. The volume of the gas particles is negligible.

4. The molecules in a real gas have finite volumes and do exert forces on each other, thus real gases do not conform to some of the assumptions of an ideal gas as stated by the kinetic molecular theory. A. True. We cannot apply ideal gas laws to real gases.

5. The average kinetic energy of a collection of gas particles is assumed to be inversely proportional to the Kelvin temperature of the gas. B. False. The average kinetic energy of a collection of gas particles is assumed to be directly proportional to the Kelvin temperature of the gas.

The given statement, "if the particles are in constant motion and there are collisions of the particles with the walls of the container, then they are the cause of the pressure exerted by the gas." is:

The given statement "The particles are assumed to exert no forces on each other; they are assumed neither to attract nor to repel each other" is:

The given statement, "The particles are so small compared with the distances between them that the volume of the individual particles can be assumed to be about 1 mL" is:

The given statement ,"The molecules in a real gas have finite volumes and do exert forces on each other, thus real gases do not conform to some of the assumptions of an ideal gas as stated by the kinetic molecular theory" is:

The given statement, "The average kinetic energy of a collection of gas particles is assumed to be inversely proportional to the Kelvin temperature of the gas" is:

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Answer: 234.8 M

Explanation:

Answer:

milliliter

Explanation:

smallest form of measuring volume from all the available choices

the titration is the most important part in determining whether

Answer:

Explanation:

A, D,E and B i think is the correct answers  

Answer:

See the answer below

Explanation:

The duration of flushing the eyes at the eyewash station in case of accidental contact with chemicals depends of the nature of the chemical.

If the chemical is known to be a non-irritant or mild-irritant one, a 5-minute washing time is recommended as the first aid. before seeking the help of a physician,

For moderate to severe irritant chemicals, an immediate 15-20 minutes washing period is recommended before seeking further medical help.

For corrosive and strong alkalis chemicals, 30 and 60 minutes washing are recommended respectively before seeking the attention of a physician.

However, if the nature of the chemical is unknown, a minimum of 20-minutes washing is generally recommended as first aid before seeking immediate medical help.

The duration of flushing the eyes at the eyewash station in case of accidental contact with chemicals depends on the nature of the chemical.

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Answer:

atomic number =17

mass number = 17+18= 35

Answer: 10

Explanation:

4Al + 2O2 --> 2Al2O3

This is the balanced equation so there are 2*2 +2*3 = 4+6 =10

Answer:

maalat ang salt

Explanation:

Answer:

Yes

Explanation:

Answer:

no

Explanation:

Answer:

Yes

Explanation:

Adding food coloring to batter or to your icing involves a chemical reaction of the two products bonding together. This bonding process starts when you add the color and mix it in, but it doesn't end straight away as the color needs some time to fully integrate and settle.

Answer:

E = 5×10⁻¹⁹ J

Explanation:

Given data:

Wavelength = 400 nm (400×10⁻⁹ m)

Energy of wave = ?

Solution:

Formula:

E = h c/λ

c = 3×10⁸ m/s

h = 6.63×10⁻³⁴ Js

Now we will put the values in formula.

E = 6.63×10⁻³⁴ Js × 3×10⁸ m/s /400×10⁻⁹ m

E = 19.89×10⁻²⁶ J.m / 400×10⁻⁹ m

E = 0.05×10⁻¹⁷ J

E = 5×10⁻¹⁹ J

Answer:

0.767 moles of ammonium phosphate are produced

Explanation:

The reaction of ammona (NH3), with phosphoric acid is:

3 NH3 + H3PO4 → (NH4)3PO4

Where 3 moles of ammonia reacts per mole of H3PO4 to produce 1 mole of ammonium phosphate.

If 2.3 moles of ammonia reacts, the moles of ammonium phosphate produced if phosphoric acid is in excess are:

2.3 moles NH3 * (1 mole (NH4)3PO4 / 3 moles NH3) =

Answer:

D) 2.8.18.7

Explanation:

because it has 7 valence electron that occupied by shells

Answer:

The force exerted on it.

Explanation:

As the law of motion states, an object at rest will remain at rest an object in motion will remain in motion unless acted upon by another force.

Answer:

In a heterogeneous mixture, the parts of the mixture are noticeably different from one another. In a homogeneous mixture, the substances are so evenly distributed that it is difficult to distinguish one substance in the mixture from another.

Answer:

[tex]200\frac{kcal}{g}[/tex]

Explanation:

Hello!

In this case, for this calorimetry problem, since the combustion 0.0500 mol of the nutrient increase the temperature of water by 5.70 °C, we can notice that the heat lost by the nutrient is gained by water in order to write:

[tex]Q_{nutrient}=-Q_{water}[/tex]

Which can be also written as:

[tex]Q_{nutrient}=-m_{water}C_{water}\Delta T_{water}\\\\Q_{nutrient}=-200 g*4.184\frac{J}{g\°C}*5.70\°C\\\\Q_{nutrient}=4769.8 J[/tex]

Thus, in terms of the grams of the nutrient:

[tex]m_{nutrient}=0.0500mol*\frac{114g}{1mol}=5.70g[/tex]

The fuel value in nutritional Cal (kcal/g) turns out:

[tex]Fuel \ Value=\frac{-4.7698kJ}{5.70g}*\frac{1kcal}{4.184kJ}=200\frac{kcal}{g}[/tex]

Best regards!

Answer:

C) 4.

Explanation:

Hello!

In this case, since the electron configuration of nickel at its ground-state, considering 28 as its atomic number and the number of electrons it has in one atom, is:

[tex]Ni^{28}:1s^2,2s^2,2p^6,3s^2,3p^6,4s^2,3d^8[/tex]

We can see it has four energy levels, 1, 2, 3 and 4, which are related to the following principal quantum number, that describes the energy of an electron in the atom and its most probable distance with respect to the nucleus.

Therefore, nickel has C) 4 different principal quantum numbers.

Best regards!

Explanation:

A chemical property of soda ash is, it is a alkaline compound

Answer:

2.500 × 10⁵ cal

Explanation:

1kcal= 1000 cal

From the analysis, the number of calories in each serving of a food with 250 Calories would be 250,000 calories.

According to the illustration:

               1 Calories = 1 kilocalories

The food package reports 250 Calories

Hence, 250 Calories = 1 x 250 kilocalories

                                      = 250 kilocalories

According to metrics, 1 kilocalories = 1,000 calories

Thus, 250 kilocalories = 250 x 1000 calories

                                      = 250,000 calories

More on unit conversion can be found here: https://brainly.com/question/19420601

Answer:

a. The carbon-carbon bond in ethane's the longest!)

Explanation:

Ethane is a chemical compound that is organic in nature. Its chemical formula is [tex]$C_2H_6$[/tex]. It has two carbon atoms and six of hydrogen atoms that is connected to the carbon atoms.

Ethane is odorless and colorless at the standard temperature and standard pressure.

The carbon to carbon atoms in ethane is connected by a single bond.

The length of single carbon-carbon bond is greater than carbon-carbon double bond and triple bond.

Thus, carbon-carbon bond length in ethane is the longest.

Answer:

Explanation:

The polarity of the 3 compounds would be in the order of

Ferrocene < Acetylferrocene < Diacetylferrocene

Your TLC data has to also support this observation . This can be checked by measuring the values of Rf ( Retention factor = distance travelled by solute/solvent ) .The Rf values also has to follow this particular order: -

Ferrocene > acetylferrocene > diacetylferrocene

2) Hexane happens to be a non-polar solvent. The polarity of hexane can be increased if some polar solvents for example, ethyl and methylene chloride etc are added

Therefore, in the increasing order of solvents polarity, we have

Hexane < 1:1 mixture of hexane: methylene chloride < 9:1 mixture of methylene chloride:

3) Chromatographic techniques all have a stationary phase in addition to a mobile phase. In the case of column chromatography, the silica gel will be the stationary phase and the solvent that will be poured will be the mobile phase.

4) The TLC and column chromatography both happen to have the same stationary phase which is the silica gel. Also, the same solvent mixture is used in both the techniques. This makes the result of the 2 to be almost the same. The difference seen between them is that, TLC works against the gravity while on the other hand column chromatography works in the direction of the gravity.

5) The key feature in the IR spectra of the acetylferrocene that will be absent in the spectra of ferrocene is the presence of carbonyl stretching frequency at close to 1700 per cm(cm-1). This peak is easily differentiated between both acetyl ferrocene and ferrocene.

with what?..................