10161.6 Lanthanum-140 can also emit beta radiation and change into cerium.
Complete the equation showing the decay of lanthanum (La) 140 into cerium (Ce).

Answer:

C. Bohr’s model showed that electron orbits had distinct radii

Explanation:

In Rutherford's atomic model, the electrons moved on arbitrary orbits, which was only due to the condition that the Coulomb force acts as a radial force. In Bohr's atomic model, only very specific orbits were allowed, which were determined by Bor's quantum condition.

Answer:

C i agree

Explanation:

3 minute would have passed from time equals zero

Calculation

The half-life of a radioisotope is the time it needs for the mass of the radioisotope to halve with respect to its original value.

In this problem, the initial mass of the radioisotope at t=0 is

m0 = 50.0 mg

We see that after t = 1 min, the mass of the isotope is

m(1 min) = 25.0 mg

so, exactly half the initial mass: this means that 1 minute is exactly the half-life of this radioisotope.

So, the amount of mass left after each minute is the following:

m (1 min ) = 25.0 mg (1 half-life)

m (2 min) = 12.5 mg (2 half-lives)

m (3 min) = 6.25 mg (3 half-lives)

so, when we are left with 6.25 mg of isotope, 3 minutes have passed, which means that 3 half-lives have passed.

Learn more about radioisotope here:

brainly.com/question/13076859

#SPJ4

Answer:

Answer:

Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune

Answer:

the greater the concentration of particles the lower the freezing point will be.

Answer: Increasing the temperature increases reaction rates because of the disproportionately large increase in the number of high energy collisions. It is only these collisions (possessing at least the activation energy for the reaction) which result in a reaction.

Explanation:

An explanation for a natural occurrence is provided by a hypothesis, which is supported by observation and testing.

A hypothesis is a well-informed prediction based on specific data that serves as the basis for more research.

Many of them dismiss evolution as "simply a hypothesis," in contrast to gravity, which must exist because it is a law. In the scientific community, the terms "theory," "facts," "laws," and "hypothesis" have extremely particular meanings that don't quite correspond to the ones we use in ordinary language. A testable hypothesis is a speculative explanation for an observable. It serves as a springboard for additional explanation. Contrarily, a theory is an explanation of a particular feature of the natural world that is supported by facts, validated hypotheses, and rules.

Learn more about hypothesis here:
https://brainly.com/question/17173491

#SPJ9

Answer:

a. 21.7824 g

b. 0.2362 g

c. 31.5273 g

Please see the answers in the picture attached below.

Explanation:

Please see the step-by-step solution in the picture attached below.

Hope this answer can help you. Have a nice day!

The mass of solute required in each case can be obtained form the stoichiometry of the reaction.

We know that the mass of each solution can be obtained from the relation;

mass/molar mass = concentration × volume

mass = concentration × volume × molar mass

a)

mass =  0.125 M  ×  1.00 L ×  174 g/mol = 21.75 g

b) mass = 0.015 M  × 375 /1000 × 42 g/mol = 0.24 g

c) mass = 0.350 M × 500/1000 × 180 g/mol =31.5 g

Learn more: https://brainly.com/question/9743981

The number of molecules in 10.0 gram of NaOH is 15 * 10²².

To solve this question, we need to understand some terms of mole concept,

Mole - It is the amount of substance containing same number of molecules or atoms as there are atoms in 12 gram of carbon-12 isotope.

Molecules - It is group of atoms bonded together, representing the smallest fundamental unit of a chemical compound taking part in chemical reaction.

Molecular weight - The sum of atomic masses of all atoms in molecules.

Avogadro number - It is the number of atoms, ions, electrons, molecules in one mole of substance. It is represented as NA.

NA = 6.0 * 10²³ (approx)

To calculate the number of molecules, we apply the formulae,

no. of molecules = moles * NA

moles = weight / molecular weight

moles = 10.0 / 40

          = 0.25

Substituting this value to calculate number of molecules,

no. of molecules = 0.25 * 6.0 * 10²³

                            = 15 * 10²²

Therefore the number of molecules of in 10.0 g of NaOH is 15 * 10²².

To know more about moles and molecules,

https://brainly.com/question/29367909

How does the size of a magnesium ion with a 2+ charge compare with that of a sodium ion with a single (+) charge?Magnesium has a larger ionic radius than sodium. The magnesium ion has a 2+ charge, while the sodium ion has a 1+ charge.

The ionic radius of an ion is determined by the number of electrons it contains, which is directly related to its atomic number. Sodium has an atomic number of 11, with 11 electrons in the atom. When one electron is removed from the outermost shell, it forms a sodium ion with a 1+ charge. The ionic radius of sodium ion is 95 picometers.Magnesium, on the other hand, has an atomic number of 12, with 12 electrons in the atom. When two electrons are removed from the outermost shell, it forms a magnesium ion with a 2+ charge. The ionic radius of the magnesium ion is 66 picometers.

Magnesium and sodium are two alkali metals that are very different from each other in terms of their properties. Magnesium is an alkaline earth metal with an  of 12, while sodium is an alkali metal with an atomic number of 11. The two metals differ in terms of the number of electrons they have, as well as in terms of the size of their ions when they are charged.Magnesium has a larger ionic radius than sodium because it has more electrons in its outer shell, which creates a greater electrostatic attraction between the electrons and the nucleus. As a result, the magnesium ion has a greater size than the sodium ion. The magnesium ion has a 2+ charge, while the sodium ion has a 1+ charge. The ionic radius of the sodium ion is 95 picometers, while the ionic radius of the magnesium ion is 66 picometers.

the size of a magnesium ion with a 2+ charge is smaller than that of a sodium ion with a single (+) charge. The difference in size can be attributed to the number of electrons in the outer shell of the ions, which determines the electrostatic attraction between the electrons and the nucleus. Magnesium has more electrons in its outer shell than sodium, which results in a greater electrostatic attraction and a larger ionic radius.

To know more about alkali metals:

brainly.com/question/18153051

#SPJ11

Answer:

Balloon filled with helium is not a mixture because the gas in it consists of solely helium atoms.

Explanation:

Explanation:

An element is a pure substance as well, because if we fill up a balloon with just helium gas, it will only contain helium atoms.

6.4mole•64.06g/1mole=409.98g

The molarity of the sample of HNO3 (aq.) is neutralized by 22.1 milliliters of 0.250 m KOH(aq.) is 0.193M

Molarity is also called as molar concentration. Molarity can be defined as the measure of the concentration of a chemical specie of the reaction in particular of a solute in a solution which is in terms of amount of substance per unit volume of solution.

The molarity can be calculated as,

M1 V1 = M2 V2

Hehe, M1 is the molarity of the acid and V1 is the volume  of the an acid. M2 is the molarity of the base and V2 is the volume of the base of the solution.

When 35.0-milliliter sample of HNO3 (aq.) is neutralized by 22.1 milliliters of 0.250 m KOH(aq.)

Putting all the values in the expression we get,

M1=M2V2/V1

    =(0.150) (32.1)/25.0

    = 0.193M

To learn more about Molarity

https://brainly.com/question/30404105

#SPJ4

Answer:

white precipitates of PbSO4 will appear

Explanation:

Now let us first consider the reaction equation;

Na2SO4(aq) + Pb(NO3)2(aq) ---->2NaNO3(aq) + PbSO4(s)

So, if i mix solutions of sodium sulfate and lead II nitrate, stir it and allow it to stand for a couple of minutes, i will begin to see the appearance of white precipitates of PbSO4.

This follows from the solubility rules. Sulphates are soluble in water except those of group II ions, Pb^2+ and silver I ion.

Answer:

crome .comxbdbshshdhdgsvsgsvdhjsjfskkt

The differences between grasses and legumes are,

The advantage and disadvantage of grasses are given below.

Advantage:

Grasses helps to keep air clean, trap carbon dioxide , reduce erosion from storm water runoff , improve soil , decreases noise pollution and reduce temperature.

Disadvantage:

The advantage and disadvantage of legumes are given below.

Advantage:

Disadvantage:

learn about legumes

https://brainly.com/question/19900764

#SPJ4

Considering the definition of molality, the molality of the KCl in the solution is 6.56 moles/kg.

Molality, or molal concentration, is the amount of a substance dissolved in a given mass of solvent. It is defined as the moles of a solute per kilogram of solvent.

The Molality of a solution is determined by the expression:

molality= number of moles of solute÷ kilograms of solvent

Molality in this case

In this case, you know:

mass of KCl= 105 g

mass molar of KCl= 74.55 g/mole

number of moles of solute= mass of KCl÷ mass molar of KCl= 105 g÷ 74.55 g/mole= 1.41 moles

Mass of solvent = 215 g of water= 0.215 kg (being 1000 g=1 kg)  

Replacing in the definition of molality:

Molality= 1.41 moles÷ 0.215 kg

Molality= 6.56 moles/kg

The molality of the solution is 6.56 moles/kg.

Learn more about molality:

brainly.com/question/20366625

#SPJ4

Answer:

The correct answer is

Explanation:

hope this helps u!!

The atmospheric pressure will be:

The pressure of the atmosphere resulting from the mercury column is 0.959 atm

What is atmospheric pressure?

The force that an object experiences from the weight of the air above it per unit area are known as atmospheric pressure.

Given: Height of mercury column = 729 mm Hg

To find: The pressure of the atmosphere

Calculation:

The atmospheric column resulting from the mercury column is calculated as follows:

1 atm =760 mm Hg

So, we can convert the 729 mm Hg to atm, and we get

Atmospheric pressure = 729 x 1 atm / 760 = 0.959 atm

Learn more about atmospheric pressure here,

https://brainly.com/question/14315894

#SPJ4

Answer:

The moving train

Explanation:

Kinetic energy is energy being used right now. So, the only object using energy right now is the moving train

Good luck on the rest of the test!

Energy + SO2(g) -----> S(g) + O2(g) is an edothermic reaction owing to te fact that energy is a reactant in the equation.

An endothermic reaction is one in  wioch energy is supplied to the system in order to enable the breakdown of bonds. Hence, the reaction vessel feels cool as energy is withdrawn from the surroundings.

The reaction;  Energy + SO2(g) -----> S(g) + O2(g) is an edothermic reaction since energy is a reactant in the equation.

Learn more about endothermic reaction: https://brainly.com/question/10373907

Answer:

the Ray's go right through it

Explanation:

the Ray's are so small they punch right through them

Answer:

Explanation:

The reason why is based in something called the plasma frequency of the metal of a mirror. A metal, as you may know, is composed of a series of atom (ion, effectively) cores - nuclei, together with some, but not all, of their bound electrons - which contribute the remaining outermost electrons of their unbound forms to a communally shared "electron sea" - kind of like a giant, distributed omnidirectional covalent bond that extends all throughout the whole metal crystal (here we're just considering a single crystal for simplicity). The electrons are quantumed out all over the full extent of the crystal and effectively form a sort of "gas" throughout and permeating the metal.

When an electromagnetic wave approaches that gas, the free charges within it - the electrons - start oscillating, and as they do so, they set up another wave going outward at the same time as the first is going in. This begins as soon as the first wave begins to impinge.

However, if the wave oscillation is fast enough, the electrons can't keep up due to their mass, and thus they are unable to form the reflected wave. The frequency at which this occurs is called the metal's plasma frequency (and is inversely proportional to the square root of the mass, so that a high mass particle would have a lower plasma frequency). The name comes from the fact that the metal can be thought of in a sense as a kind of "solid plasma" - ions with free electrons, the difference with what most people think of as a "plasma" being here the ions are not free to move about of their own accord.

The right answer is true. It is accurate to say that because liquids and solids are almost incompressible, pressure has little impact on their solubility.

We are aware that the concept of compressibility refers to how the study object's qualities can alter simply by applying pressure on it. Whether or not a solid, liquid, or gas can have a solubility that is influenced by the substance's pressure depends on the compressibility factor. We must keep in mind that when we discuss pressure in science, our thoughts must immediately turn to the force per unit area of the substance that is being investigated in each specific example. Because the solid and liquid have a fixed volume while the gas does not, the gas will take on the volume of the container it is carried in, proving that the solid and liquid are less compressible than the gas.

Learn more about compressibility here:

brainly.com/question/23026638

#SPJ4

It is accurate to say that because liquids and solids are nearly incompressible, pressure has minimal impact on their solubility.

Pressure has very little or no impact on how easily particles dissolve in liquid. This is due to the fact that solids and liquids are largely unaffected by changes in pressure due to their incompressibility. The solubility, which depends on gas pressure, is a measurement of the concentration of dissolved gas particles in the liquid. A gas's solubility increases with higher pressure while falling with lower pressure because of an increase in collision frequency. · The solubility of liquids and solids is mostly unaffected by external pressure. The concentration of dissolved gas molecules in the solution at equilibrium is higher at higher pressures because the concentration of molecules in the gas phase rises with increasing pressure.

To know  more about solubility click here brainly.com/question/28170449

#SPJ4

Oxidizing acids, such as nitric acid, can explode when mixed with what type of incompatible chemicals like alcohol, or charcoal.

An oxidizing acid is a Brønsted acid that is a strong oxidizing agent. most Brønsted acids can act as oxidizing agents because the acidic proton can be reduced to hydrogen gas. a few acids include other structures that act as stronger oxidizing agents than hydrogen ions.

Oxidizing acids include concentrated perchloric acid, nitric acid, iodic acid, chromic acid, and the glass cleansing mixture of chromium trioxide and sulfuric acid.

learn more about acids here https://brainly.com/question/25148363

#SPJ4

Answer:

Any solid may be sublimed if its temperature and pressure are below its triple point. For example, if you were to freeze water into ice and cool it further and then reduce the pressure, you could get ice to sublime. Some other examples include: Dry ice (solid CO2) which sublimes at atmospheric pressure and -78 C, and C60 (buckyballs) which sublimes at atmospheric pressure at around 800 K.

Explanation:

The value that would be put in the numerator of this calibration would be 10° C .

The process of calibrating an instrument involves setting it up such that it can produce results for samples that are within a reasonable range. A key component of instrumentation design is eliminating or reducing conditions that lead to faulty measurements.

In order to ascertain the mistake or confirm the precision of the unknown value of the DUT, a calibration is normally carried out. As a simple illustration, you may calibrate a DUT thermometer by measuring its temperature in water at its known boiling point (212 degrees Fahrenheit) in order to determine the thermometer's inaccuracy.

To obtain accurate readings, a thermometer must be calibrated because its precision is susceptible to deterioration over time. Thermometers can change over time for a variety of reasons.

Hence, The value that would be put in the numerator would be 10° C because difference between two marked values or space between two marked value is 10.

To learn more about Calibration of thermometer refer - https://brainly.com/question/25034625

#SPJ9

Answer:

D. Ruler

Explanation:

Use the formula to find the volume of a cuboid by measuring the length, width, and height and multiplying all of them by each other.

Answer:

0.000001 joule

Explanation:

brainlest?