HELP CHEMISTRY PLEASE I BEG U 25 POINTS

1 What would be the effect on the nucleus of an atom if it emitted one beta particle and one gamma ray?

no change in either atomic number or in mass number

a decrease of one in atomic number and a decrease of two in mass number

an increase of one in atomic number and no change in mass number

an increase of one in atomic number and an increase of two in mass number

2 Which statement is true regarding radioactive particles subjected to an electric field?

alpha rays would be deflected toward a negative source

beta rays would be deflected toward a positive source

gamma radiation would not be deflected toward either a negative or a positive source

all of the above statements are correct

3 What would be the effect on the nucleus of an atom if it emitted one alpha and then one beta particle?

a decrease of two in atomic number and a decrease of four in mass number

a decrease of one in atomic number and a decrease of four in mass number

a decrease of one in atomic number and an increase of one in mass number

an increase of one in atomic number and a decrease of two in mass number

4Nuclear decay by beta particle emission is more common in atoms of elements that:

have an atomic number greater than 83

have a high proton to neutron ratio

have a high neutron to proton ratio

have a low proton to neutron ratio

Answer:

0.077 M

Explanation:

Molarity is the representation of the solution.

Molarity:

It is amount of solute in moles per liter of solution and represented by M

Formula used for Molarity

                    M = moles of solute / Liter of solution . . . . . . . . . . (1)

Data Given :

The concentration of half normal (NaCl) saline = 0.45g / 100 g

So,

Volume of Solution =  100 g = 100 mL

Volume of Solution in L =  100 mL / 1000

Volume of Solution =  0.1 L

molar mass of NaCl = 58.44 g/mol

Now to find number of moles of Nacl

               no. of moles of NaCl = mass of NaCl / molar mass

               no. of moles of NaCl =  0.45g / 58.44 g/mol

               no. of moles of NaCl =  0.0077 g

Put values in the eq (1)

                  M = moles of solute / Liter of solution . . . . . . . . . . (1)

                  M = 0.0077 g / 0.1 L

                  M = 0.077 M

So the molarity of half-normal saline solution (0.45% NaCl) = 0.077 M

Final answer:

The calculated density of the water sample should be reported with two significant figures, which is the same as the measurement with the least number of significant figures used in the calculation (the volume in this case).

Explanation:

When determining the number of significant figures in a calculated density, you must look at the measurements used in the calculation. In this case, the mass of the water sample is given as 1.060 g which has four significant figures, and the volume is 1.0 mL which has two significant figures. According to the rules for significant figures, the number of significant figures in the result of a division should be the same as the measurement with the least number of significant figures. Therefore, the density calculated should be reported with two significant figures.

Answer:

A. expands

Ice molecules come closer together becoming more compact ^^

Answer:

2.1 M KOH is required.

Explanation:

It is an example of acid-base neutralization reaction.

KOH  +  HBr  ---->  KBr  +  [tex]H_{2}O[/tex]

Base     Acid           Salt        

When two component react then the number of moles of both the component should be same, therefore the number of moles and acids and bases should be the same in the following .

Molarity= [tex]\frac{\textrm{No. of moles}}{\textrm{Volume of the particular solution}}[/tex]

No.of moles= Molarity × Volume of the Particular Solution

Therefore,

[tex]M_{1} V_{1} = M_{2} V_{2}[/tex]------------------------------(1)

where

[tex]M_{1}[/tex]= Molarity of Acid

[tex]V_{1}[/tex]= Volume of Acid

[tex]M_{2}[/tex]= Molarity of Base

[tex]V_{2}[/tex]= Volume of Base

[tex]M_{1}[/tex]=3.5 M

[tex]V_{1}[/tex]=15 mL

[tex]V_{2}[/tex]=25 mL

[tex]M_{2}[/tex]=??(in M)

Plugging in Equation 1,

3.5 × 15 = [tex]M_{2} [/tex] × 25

[tex]M_{2} [/tex]=[tex]\frac{3.5 * 15}{25}[/tex]

[tex]M_{2} [/tex]=2.1 M

We have that for the Question "What volume of 0.20MNaCl(aq) contains 10.0g of NaCl (molar mass 58g/mol)?" it can be said that The volume of 0.20MNaCl(aq) contains 10.0g of NaCl (molar mass 58g/mol) is

V=0.862L

From the question we are told

What volume of 0.20MNaCl (aq) contains 10.0g of NaCl (molar mass 58g/mol)?

Generally the equation for the  morality  is mathematically given as

[tex]M=\frac{moles of NaCl}{Volume of sol}\\\\0.20=\frac{10/58}{V}\\\\[/tex]

V=0.862L

Therefore

The volume of 0.20MNaCl(aq) contains 10.0g of NaCl (molar mass 58g/mol) is

V=0.862L

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To find the volume of 0.20 M NaCl solution containing 10.0 g of NaCl, calculate the number of moles of NaCl and divide by the molarity. It results in a volume of 0.862 liters.

To calculate the volume of 0.20 M NaCl solution that contains 10.0 g NaCl, we will begin by converting the mass of NaCl into moles. Next, we will use the molarity of the solution to find out the volume that contains these moles.

Using the molar mass of NaCl (58 g/mol), we calculate the number of moles of NaCl:

Number of moles of NaCl = mass (g) / Molar mass (g/mol)
Number of moles of NaCl = 10.0 g / 58 g/mol
Number of moles of NaCl = 0.1724 mol

Molarity (M) is defined as the number of moles of solute per liter of solution. We rearrange the molarity equation to solve for volume:

Volume (L) = Number of moles of solute / Molarity (M)
Volume (L) = 0.1724 mol / 0.20 M
Volume = 0.862 L

Therefore, 0.862 liters (or 862 milliliters) of 0.20 M NaCl solution contains 10.0 grams of NaCl.

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Answer:

If the electronegativity difference between bonded atoms are too much high ionic bonds are formed if the electronegativity diference is 0.4 or less than 0.4 non polar covalnet bond formed the difference greater than 0.4 polar covalent bond formed.

Explanation:

Ionic bond:

It is the bond which is formed by the transfer of electron from one atom to the atom of another element.  

Both bonded atoms have very large electronegativity difference. The atom with large electronegativity value accept the electron from other with smaller value of electronegativity.

For example:

Sodium chloride is ionic compound. The electronegativity of chlorine is 3.16 and for sodium is 0.93. There is large difference is present. That's why electron from sodium is transfer to the chlorine. Sodium becomes positive and chlorine becomes negative ion.

Covalent bond:

It is formed by the sharing of electron pair between bonded atoms.  

The atom with larger electronegativity attract the electron pair more towards it self and becomes partial negative while the other atom becomes partial positive.

For example:

In water the electronegativity of oxygen is 3.44 and hydrogen is 2.2. That's why electron pair attracted more towards oxygen, thus oxygen becomes partial negative and hydrogen becomes partial positive.

Answer:

True

Explanation:

Answer:

d , before the molten rock becomes lava, it is first magma, and most people know that lava is ejected from volcanoes

Magma reaches the Earth's surface through volcanoes, then turns into lava.  The correct option is option D among all the given options.

A volcano is a crack inside this crust of a planet, including such Earth, that permits hot lava, volcanism, as well as gases to emerge from such a magma chamber under the surface.

Volcanoes are most commonly located where tectonic plates either diverging or converging on Earth, and the majority are found underwater. For example, the Mid-Atlantic Ridge is a mid-ocean ridge. Magma reaches the Earth's surface through volcanoes, then turns into lava.

Therefore, magma reaches the Earth's surface through volcanoes, then turns into lava. The correct option is option D  among all the given options.

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A fine powder dissolves quickly, this solution can more quickly be absorbed and begin working. Therefore, the correct option is option D.

The term "dissolution" refers to the action of dissolving or creating a solution. When a solute dissolves, it splits into atoms or molecules, with molecules of the solvent surrounding each ion or molecule. Solvation is the term used to describe interactions between solvent molecules and solute particle.

Solutes are the other elements of the solution that are present at comparatively lower concentrations. Several headache medications are consumed after being dissolved in water from fine powders. These drugs assert that they function more quickly than other drugs. This is true as  a fine powder dissolves quickly, this solution can more quickly be absorbed and begin working.

Therefore, the correct option is option D.

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Answer:

13.7 moles

Explanation:

Given data:

Number of moles calcium carbonate = ?

Formula units calcium carbonate= 8.23 × 10²⁴

Solution:

The given problem will solve by using 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.

For example,

18 g of water = 1 mole = 6.022 × 10²³ molecules of water

1.008 g of hydrogen = 1 mole = 6.022 × 10²³ atoms of hydrogen

For 8.23 × 10²⁴ formula units:

one mole = 6.022 × 10²³ formula units

8.23 × 10²⁴ formula units × 1 mole /6.022 × 10²³ formula units

13.7 moles

Answer:

The oxidation state of sodium is +1 and chlorine is -1.

Explanation:

Oxidation:

Oxidation involve the removal of electrons and oxidation state of atom of an element is increased.

Reduction:

Reduction involve the gain of electron and oxidation number is decreased.

Consider the following reactions.

2Na + Cl₂ → 2NaCl

The oxidation state of chlorine and sodium on left side is 0. After the reaction between them oxidation state is changed. Sodium is oxidized and chlorine is reduced. The oxidation sate of sodium is +1 while that of chlorine is -1. Sodium is reducing agent while chlorine is oxidizing agent.

Oxidizing agents:

Oxidizing agents oxidize the other elements and itself gets reduced.

Reducing agents:

Reducing agents reduced the other element are it self gets oxidized.

Answer: four hydrogen atoms and one carbon atom to form methane (CH4)

Explanation: Study island

The elements most likely to form a covalent compound are four hydrogen atoms and one carbon atom to form methane (CH4). For an ionic compound, lithium and fluorine combine to form lithium fluoride (LiF).

Atoms of different elements can combine chemically to form compounds, primarily through ionic or covalent bonding. The elements most likely to form a compound bound tightly together with covalent bonds are none other than non-metals which share electrons. The answer to the question 'Which of the following elements would be most likely to form a compound bound tightly together with covalent bonding?' is C, which involves four hydrogen atoms and one carbon atom forming methane (CH4). Methane is an example of a molecule formed with covalent bonds where the central carbon atom shares electrons with four hydrogen atoms.

Regarding which two elements could form an ionic compound, the answer would be C: 3 lithium and 9 fluorine. Lithium, being a metal, tends to lose electrons, while fluorine, a non-metal, has a tendency to gain electrons. This transfer of electrons from lithium to fluorine forms an ionic compound known as lithium fluoride (LiF).

Answer:

0.5 moles of HgO will produced 0.25 moles of oxygen

Explanation:

Given data:

Number of moles of HgO = 0.5 mol

Number of moles of oxygen = ?

Solution:

Chemical equation;

2HgO   →  2Hg + O₂

WE will compare the moles of HgO with oxygen from balance chemical equation.

                                HgO        :         O₂

                                   2           :          1

                                    0.5       :          1/2×0.5 =0.25 mol

So 0.5 moles of HgO will produced 0.25 moles of oxygen.

Answer:

T₂ = 16.7  °C

Explanation:

Given data:

Initial volume = 150.0 mL

Temperature = 25.0 °C

Final volume = 100 mL

Final temperature = ?

Solution:

V₁ /T₁ = V₂/T₂

T₂ = V₂ . T₁/V₁

T₂ = 100 mL .25 °C / 150.0 mL

T₂ = 2500 mL.  °C / 150.0 mL

T₂ = 16.7  °C

Final Answer:

Upon cooling from a volume of 150.0 mL to 100.0 mL at constant pressure, the temperature of the carbon monoxide gas is estimated to be approximately -74.4 °C, as determined using Charles's Law.

Explanation:

To ascertain the new temperature of carbon monoxide as it undergoes cooling from 150.0 mL to 100.0 mL at a constant pressure, Charles's Law is applied. Charles's Law asserts that the volume of a gas is directly proportional to its temperature when pressure remains constant, and this relationship can be expressed mathematically as V1/T1 = V2/T2, where V1 is the initial volume, T1 is the initial temperature, V2 is the final volume, and T2 is the final temperature.

Given an initial temperature (T1) of 25.0 °C, it needs conversion into kelvins by adding 273.15 to the Celsius temperature, resulting in T1 = 25 + 273.15 = 298.15 K. The initial volume (V1) is 150.0 mL, and the final volume (V2) is 100.0 mL. Utilizing Charles's Law, we can now determine the final temperature (T2).

Applying Charles's Law, we derive:

V1/T1 = V2/T2

(150.0 mL) / (298.15 K) = (100.0 mL) / (T2)

T2 = (100.0 mL) * (298.15 K) / (150.0 mL)

T2 = 198.7667 K

To express the temperature in Celsius, we subtract 273.15 from the temperature in kelvins:

T2 = 198.7667 K - 273.15

T2 ≈ -74.3833 °C

Thus, the new temperature of the carbon monoxide after cooling is approximately -74.4 °C.

Answer:

C)

Explanation:

Because The air up 3 Kilometers is too cold for raindrops and sleet. plus ozone is in the stratosphere

Answer:

A scandium-48 nucleus undergoes beta-minus decay to produce a titanium-48 nucleus.

[tex]\rm ^{48}_{21}Sc \to ^{48}_{22}Ti + ^{\phantom{1}\,0}_{-1}e^{-} + \bar{\mathnormal{v}}_e[/tex].

Explanation:

There are two types of beta decay modes: beta-minus and beta-plus.

In both decay modes, the mass number of the nucleus stays the same.

However, in a beta-minus decay, the atomic number of the nucleus increases by one. In a beta-plus decay, the atomic number decreases by one.

Each beta-minus decay releases one electron and one electron antineutrino. Each beta-plus decay releases one positron and one electron neutrino.

Look up the atomic number and relative atomic mass for the element scandium.

This question did not specify whether the decay here is beta-plus or a beta-minus. However, the relative atomic mass of this element can give a rough estimate of the mode of decay.

Each element (e.g, [tex]\rm Sc[/tex]) can have multiple isotopes. These isotopes differ in mass. The relative atomic mass of an element is an average  across all isotopes of this element. This mass is weighted based on the relative abundance of the isotopes. Its value should be closest to the most stable (and hence the most abundant) isotope.

The mass number of scandium-48 is significantly larger than the relative atomic mass of this element. In other words, this isotope contains more neutrons than isotopes that are more stable. There's a tendency for that neutron to convert to a proton- by beta-minus decay, for example.

The atomic number of the nucleus will increase by 1. [tex]21 + 1 = 22[/tex]. That corresponds to titanium. The mass number stays the same at [tex]48[/tex]. Hence the daughter nucleus would be titanium-48. Note that two other particles: one electron and one electron [tex]\rm e^{-}[/tex] and one antineutrino [tex]\bar{v}_{\text{e}}[/tex] (note the bar.) The neutrino helps balance the lepton number of this reaction.

The balanced equation for the transmutation that occurs when a scandium-48 nucleus undergoes beta decay is:[tex]\[ \ce{^48_21Sc - > ^48_22Ti + ^0_{-1}e} \][/tex]

  Beta decay is a type of radioactive decay in which a beta particle (an electron or a positron) is emitted from an atomic nucleus. In the case of scandium-48 [tex](\( \ce{^48_21Sc} \))[/tex], beta decay means that a neutron in the nucleus is converted into a proton, an electron (beta particle), and an electron antineutrino. The proton remains in the nucleus, increasing the atomic number by one, while the electron and antineutrino are emitted.

 The atomic number of scandium is 21, and after beta decay, the atomic number increases by one to become 22, which corresponds to the element titanium (Ti). The mass number (the total number of protons and neutrons in the nucleus) remains unchanged at 48 because a neutron is converted into a proton without any change in the number of nucleons.

 The symbol [tex]\( \ce{^0_{-1}e} \)[/tex] represents the beta particle, which is an electron. The charge of the electron is -1, and it has essentially no mass compared to a proton or neutron, hence the mass number being 0.

Therefore, the product of the beta decay of scandium-48 is titanium-48 [tex](\( \ce{^48_22Ti} \))[/tex], and the balanced equation includes the original nucleus, the resulting nucleus, and the emitted beta particle:

[tex]\[ \ce{^48_21Sc - > ^48_22Ti + ^0_{-1}e} \][/tex]

 This equation shows the conservation of mass and charge, which are fundamental principles in nuclear reactions. The mass number (48) is conserved, and the total charge is also conserved, with the scandium nucleus having a charge of +21, the titanium nucleus having a charge of +22, and the electron having a charge of -1, balancing the total charge before and after the decay.

Answer:

well she can test both of the soap by putting one on and plate and another on the other plate and which ever is cleaner is your answer

To calculate an object's density, you need to know its mass and volume. Mass measures the total quantity of matter, and volume measures the space it occupies. Density is found by dividing mass by volume.

To calculate the density of an object, you need to know two specific quantities: mass and volume. Mass is a measure of the total quantity of matter in the object and is often measured in grams or kilograms. Volume, on the other hand, is a measure of the space occupied by the object, which can be measured in cubic centimeters, liters, or other units of volume. Density is then calculated by dividing the mass by the volume of the object. Therefore, knowing the space it occupies and the total quantity of matter is essential for calculating density.

Answer:

C. Blindness

Explanation:

Just took the test, hope I can help!

Shaken Baby Syndrome causes the death of many young children. Shaken infant syndrome survivors may need lifetime medical treatment for issues like Partial or complete blindness.

Developmental delays, academic difficulties, or behavioral concerns. intellectual handicap epilepsy diseases. Movement and muscle coordination are both impacted by cerebral palsy, a condition.

The brain and vision are severely injured by the shaken baby syndrome. Although retinal hemorrhages are very common, brain damage is more frequently the cause of vision loss. On presentation, the patient's pupillary response and visual response displayed a strong connection with survival.

This can happen when wounded nerve cells release chemicals that worsen your child's brain's lack of oxygen. Retinal bleeding: backward bleeding in your child's retinas

Thus, option C is correct.

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Structure of  2-methylpropane is CH₃─CH(CH₃)─CH₃.

to draw the structure of 2-methylpropane.

To draw the structure of 2-methylpropane:

1. Start with a propane backbone, which consists of a chain of three carbon atoms.

2. Identify the position of the methyl (CH₃) group at the second carbon atom in the chain.

3. Attach the methyl group to the second carbon atom to represent 2-methylpropane.

By following these steps, you can accurately draw the structure of 2-methylpropane.

Answer:

Explanation:

Physical property:

Physical properties involve that property of matter which can be observed without changing the identity or undergoing chemical change or any other reaction. For example, taste, color, odor, density etc.

Chemical property:

Chemical properties observed during the chemical reaction. These properties changed the identity of substance.  For example, reactivity, stability, oxidation state, flammability etc.

A) Hydrogen is a colorless, tasteless, and odorless gas.

This statement shows the physical property of hydrogen.

B) Hydrogen is very combustible in the presence of oxygen.

This statement shows the chemical property of hydrogen

C) Hydrogen is very reactive with most elements.

This statement shows the chemical property of hydrogen

D) Hydrogen is the least dense of all elements.

This statement shows the physical property of hydrogen.

Answer:

for people doing ed

Explanation:

1. physical

2. chemical

3. chemical

4. physical

Answer: c. balance

Explanation: Mass is the amount of matter contained in a body.

Relative and average atomic mass both describe properties of an element related to its different isotopes. Out of these two Relative atomic mas is more accurate. Therefore, the correct option is option B.

Mass defines the quantity of a substance. It is measured in gram or kilogram. Average mass is the mass of atoms of an element that are isotopes. It can be calculated by multiplying mass of a isotope to natural abundance of that isotope.

Average atomic mass = (mass of first isotope× percent abundance of first isotope)+(mass of second isotope× percent abundance of second isotope)

The relative mass is the mass that is with respect to mass of a matter that is considered as standard. In chemistry relative mass is equal to the mass of one-twelfth the mass of C-12 isotope . Balance is the tool that is used to measure mass.

Therefore, the correct option is option B.

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Answer:

C ) Cu(s) + 2AgNO3(aq)

Explanation:

A chemical reaction is represented by a chemical equation which show the reactant and products. Reactants are written on left side of arrow while products are written on right side. The number of atoms are remain same however arrangement of atoms is different on both side.

For example:

Cu(s) + 2AgNO3(aq) →   2Ag + Cu(NO3)2

In this reaction Cu and AgNO3 are reactants while Ag and Cu(NO3)2 are products.The number of atoms are same on both side however arrangement of atoms is different.

Answer: A & C

Explanation:

Answer:

1) Iron iodide and silver carbonate.

2) 6AgI + Fe(CO₃)₃ → 2FeI₃ + 3Ag₂CO₃

3)  double displacement reaction

Explanation:

Chemical equation:

AgI + Fe(CO₃)₃ → FeI₃ + Ag₂CO₃

Balanced chemical equation:

6AgI + Fe(CO₃)₃ → 2FeI₃ + 3Ag₂CO₃

The given reaction is double displacement reaction. The cation and anion of both reactants are interchanged and form iron iodide and silver carbonate.

Double replacement:

It is the reaction in which two compound exchange their ions and form new compounds.

AB + CD → AC +BD

Answer:

[tex]\large \boxed{\text{E) 721 K; B) 86.7 g}}[/tex]

Explanation:

Question 7.

We can use the Combined Gas Laws to solve this question.

a) Data

p₁ = 1.88 atm; p₂ = 2.50 atm

V₁ = 285 mL;  V₂ = 435 mL

T₁ = 355 K;     T₂ = ?

b) Calculation

[tex]\begin{array}{rcl}\dfrac{p_{1}V_{1}}{T_{1}}& =&\dfrac{p_{2}V_{2}}{T_{2}}\\\\\dfrac{1.88\times285}{355} &= &\dfrac{2.50\times 435}{T_{2}}\\\\1.509& = &\dfrac{1088}{T_{2}}\\\\1.509T_{2} & = & 1088\\T_{2} & = & \dfrac{1088}{1.509}\\\\ & = & \textbf{721K}\\\end{array}\\\text{The gas must be heated to $\large \boxed{\textbf{721 K}}$}[/tex]

Question 8. I

We can use the Ideal Gas Law to solve this question.

pV = nRT

n = m/M

pV = (m/M)RT = mRT/M

a) Data:

p = 4.58 atm

V = 13.0 L

R = 0.082 06 L·atm·K⁻¹mol⁻¹

T = 385 K

M = 46.01 g/mol

(b) Calculation

[tex]\begin{array}{rcl}pV & = & \dfrac{mRT}{M}\\\\4.58 \times 13.0 & = & \dfrac{m\times 0.08206\times 385}{46.01}\\\\59.54 & = & 0.6867m\\m & = & \dfrac{59.54}{0.6867 }\\\\ & = & \textbf{86.7 g}\\\end{array}\\\text{The mass of NO$_{2}$ is $\large \boxed{\textbf{86.7 g}}$}[/tex]

5175 Newtons

We are given;

We are required to calculate the work input;

Input force =Output force ÷ Mechanical advantage

Input force = 345 N × 15

                  = 5175 Newtons

Thus, the work input of a pulley system is 5175 N

Answer:

8.2x10^22 molecules ( 1 mol / 6.022 x 10^23 molecules ) ( 789.44 g / 1 mol ) = 107.50 grams N2I6

Explanation:

Answer:

Explanation:

1) How much would 1.34 moles of carbon weigh?

Given data:

Moles of carbon = 1.34 mol

Mass of carbon = ?

Solution:

Formula:

Molar mass of carbon = 12 g/mol

Number of moles = mass/molar mass

Mass =  moles × molar mass

Mass = 1.34 mol × 12 g/mol

Mass =  16.08 g

So 1.34 moles of carbon have 16.08 g mass.

2) How many  moles of magnesium in 24.32 g?

Given data:

Mass of magnesium = 24.32 g

Moles of magnesium = ?

Solution:

Molar mass of magnesium = 24.305 g/mol

Number of moles = mass/molar mass

Number of moles = 24.32 g/24.305 g/mol

Number of moles = 1 mol

Thus 24.32 g of magnesium have one mole of Mg.

3) How many atoms of lithium in 4.00 g of lithium?

Given data:

Mass of lithium = 4 g

Atoms of lithium = ?

Solution:

The given problem will solve by using 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.

Moles of lithium:

Number of moles = mass/molar mass

Number of moles = 4 g / 6.9 g/mol

Number of moles = 0.6 mol

1 mole =  6.022 × 10²³  atoms

0.6 mol ×  6.022 × 10²³  atoms / 1 mol = 3.6 × 10²³  atoms

4) How much would 4.45 ×10²² atoms of U weigh?

Given data:

Number of atoms of uranium =  4.45 ×10²² atoms

Mass of uranium = ?

Solution:

one mole = 6.022 × 10²³  atoms

4.45 ×10²² atoms × 1 mol / 6.022 × 10²³  atoms

0.74 ×10⁻¹ mol

0.074 mol

Mass of uranium:

Mass = number of moles  × molar mass

Mass = 0.074 mol × 238 g/mol

Mass = 17.6 g

Answer:

The number of energy levels increased atomic radius also goes to increase.

Explanation:

Atomic radius  trend along period.

As we move from left to right across the periodic table the number of valance electrons in an atom increase. The atomic size tend to decrease in same period of periodic table because the electrons are added with in the same shell. When the electron are added, at the same time protons are also added in the nucleus. The positive charge is going to increase and this charge is greater in effect than the charge of electrons. This effect lead to the greater nuclear attraction. The electrons are pull towards the nucleus and valance shell get closer to the nucleus. As a result of this greater nuclear attraction atomic radius decreases and ionization energy increases because it is very difficult to remove the electron from atom and more energy is required.

Atomic radii trend along group:

As we move down the group atomic radii increased with increase of atomic number. The addition of electron in next energy level cause the atomic radii to increased. The hold of nucleus on valance shell become weaker because of shielding of electrons thus size of atom increased.

The number of energy levels in an atom affects its radius. Moving down a group increases the energy levels and atomic radius, while moving across a period increases the effective nuclear charge and decreases the atomic radius.

The number of energy levels in an atom has an effect on its radius. As we move down a group in the periodic table, the number of energy levels increases, leading to an increase in the atomic radius. As we move across a period, the number of energy levels remains the same, but the effective nuclear charge experienced by the electrons increases. This causes the electrons to be pulled in tighter to the nucleus and results in a decrease in the atomic radius.

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Answer:

Avogadro says one mole of particles contain 6.02 x 10^23 particles. Hence, 2 moles of water molecules contains 2 x 6.02 x 10^23 molecules.

Explanation:

Answer:

one mole of particles contain 6.02 x 10^23 particles. Consequently, 2 moles of water particles contain 2 x 6.02 x 10^23 atoms.

Explanation: