can u pls help me with this question ​

Answer:

Neptunium, Protactinium, plutonium and more

Explanation:

Answer:

D)

Explanation:

Answer:

the last one

Explanation:

Answer:

C.) That all matter was composed of earth, fire, water and air

Explanation:

Just took the test

Answer:

66.5753 amu

Explanation:

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

Isotope A (⁶⁵X):

Mass of A = 65.0457 amu

Abundance of A = 20.53%

Isotope B (⁶⁷X):

Mass of B = 66.9704 amu

Abundance of B = 79.47%

Atomic mass of X =?

The atomic mass of X can be obtained as follow:

Atomic mass = [(mass of A × A%)/100] + [(mass of B × B%)/100]

= [(65.0457 × 20.53)/100] + [(66.9704 × 79.47)/100]

= 13.3539 + 53.2214

= 66.5753 amu

Therefore, the atomic mass of X is 66.5753 amu.

Element X, with an atomic mass of 66.58 amu, has 2 naturally occurring isotopes, ⁶⁵X (65.0457 amu, 20.53%) and ⁶⁷X (66.9704 amu,  79.47%).

The average atomic mass (atomic mass) of an element is the sum of the masses of its isotopes, each multiplied by its natural abundance.

Element X has 2 isotopes:

We can calculate the average atomic mass of X using the following expression.

mX = m⁶⁵X × ab⁶⁵X + m⁶⁷X × ab⁶⁷X

mX = 65.0457 amu × 0.2053 + 66.9704 amu × 0.7947

mX = 66.58 amu

Element X, with an atomic mass of 66.58 amu, has 2 naturally occurring isotopes, ⁶⁵X (65.0457 amu, 20.53%) and ⁶⁷X (66.9704 amu,  79.47%).

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Answer:

No, a mole of oxygen is about 16 grams

Explanation:

Answer:

blood circulation The circulation of blood refers to its continual flow from the heart, through branching arteries, to reach and traverse the microscopic vessels in all parts of the body, reconverging in the veins and returning to the heart, to flow thence through the lungs and back to the heart to start the circuit.

That is the answer. Your welcome

Answer:

d. substance #5 in a gas at 78' F

Explanation:

Diffusion in substances simply has to do with the movement of the particles of a substance from one point to another.

The rate of diffusion varies in gases, liquids and solids. Gas molecules are usually more energetic than molecules of solids and liquids. Gases and are also in constant random motion at high velocities.

Therefore, substance #5 in a gas at 78' F will have the greatest diffusion rate.

Answer:

Explanation:

Answer:

A

Explanation:

Answer:

Burning gasoline in a lawnmower is a chemical change.

Explanation:

Here, a combustion reaction takes place. Freezing water to make ice cubes, melting gold to make jewellery and boiling water for soup are examples of physical change since, only a change in physical state takes place.

Answer:

weighing balance/analytical balance

Graduated cylinder/buret

Explanation:

The mass of the evaporating basin could be measured using a weighing balance or an analytical balance. Both are classified as weighing scales but the analytical balance can measure the mass of objects up to 4 decimal places, thus, providing better accuracy in measurement than ordinary weighing balance that can only measure up to 2 decimal places.

In order to measure 50 cm3 of the sea water, a graduated cylinder or a buret can be used. Both equipment can measure up to the same decimal places and, thus, have virtually the same accuracy.

Answer:

Their nuclear symbols are therefore 1H, 2H, and 3H.

Explanation:

Answer:

0.0032mm

Explanation:

Given dimension:

Measurement  = 3.2 x 10⁻³mm

Unknown:

Write in standard notation from scientific notation = ?

Solution:

The standard notation is the way we normally write.

   For example;   standard notation of 1 million is 1000000

Now;

        3.2 x 10⁻³  =   [tex]\frac{3.2}{1000}[/tex]    = 0.0032mm

3.2x10⁻³ mm in standard notation is 0.0032 mm. The normal or generally accepted manner of representing or expressing anything is referred to as standard notation.

Standard notation refers to the conventional or widely accepted way of representing or expressing something. In mathematics, for example, standard notation refers to the commonly used symbols and formats for writing mathematical expressions, equations, or numbers. The use of standard notation ensures uniformity, ease of understanding, and communication among mathematicians and students. Powers of 10 are used in scientific notation to express extremely large or extremely small quantities. 3.2x10⁻³ mm in standard notation is 0.0032 mm.

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Answer:

0.069 M

Explanation:

Equation of the reaction:

H₂SO₄(aq) + 2NaOH(aq) ⇒ Na₂SO₄(aq)+2H₂O(l)

From the equation above, 2 mole of NaOH is required to  reach equivalent point with 1 mole of H₂SO₄.

n'CV = nC'V' ........................ Equation 1

Where n and n' = are number of moles of acid and base respectively, C and C' = are molarities of acid and base respectively, V and V' are volumes of acid and base respectively.

make C the subject of the equation

C = nC'V'/n'V.............................. Equation 2

Given: n = 1, n' = 2, C' = 0.11 M, V = 25 mL, V' = 31.43 mL

Substitute into equation 2

C = (1×0.11×31.43)/(25×2)

C = 0.069 M.

Hence the molarity of H₂SO₄ is 0.069 M

Answer:

44Kj

Explanation:

These are the equations for the reaction described in the question,

Vaporization which can be defined as transition of substance from liquid phase to vapor

H2(g)+ 1/2 O2(g) ------>H2O(g). Δ H

-241.8kj -------eqn(1)

H2(g)+ 1/2 O2(g) ------>H2O(l).

Δ H =285.8kj ---------eqn(2)

But from the second equation we can see that it moves from gas to liquid, we we rewrite the equation for vaporization of water as

H2O(l) ------>>H2O(g)---------------eqn(3)

But the equation from eqn(2) the eqn does go with vaporization so we can re- write as

H2O ------> H2(g)+ 1/2 O2(g)

Δ H= 285.8kj ---------------eqn(4)

To find Delta h of the vaporization of water at these conditions, we sum up eqn(1) and eqn(4)

Δ H=285.8kj +(-241.8kj)= 44kj

Answer:

13896g

Explanation:

volume = 4.50×8.00×20.00 = 720 cm³

mass = density × volume

mass= 19.3 × 720 = 13896g

Answer:

2CH₃OH + 3O₂ → 2CO₂ + 4H₂O

Explanation:

A complete reaction for when any organic compound burns in air, produces only water and carbon dioxide. It does so by reacting with the oxygen gas (O₂) present in air.

In the case of methanol (CH₃OH) combustion, the balanced reaction is:

2CH₃OH + 3O₂ → 2CO₂ + 4H₂O

To determine which object has the least volume, we can calculate the volume of each object using the formula of density. From this, Object C has the smallest volume of 20 cm³ among Objects A, B, and C.

The formulae of volume:

Volume = Mass / Density

Let's calculate the volumes of objects A, B, and C:

For Object A:

Density = 2.0 g/cm³

Mass = 100 g

Volume of A = Mass / Density

Volume of A = 100 g / 2.0 g/cm³

Volume of A = 50 cm³

For Object B:

Density = 0.8 g/cm³

Mass = 240 g

Volume of B = Mass / Density

Volume of B = 240 g / 0.8 g/cm³

Volume of B = 300 cm³

For Object C:

Density = 5.0 g/cm³

Mass = 100 g

Volume of C = Mass / Density

Volume of C = 100 g / 5.0 g/cm³

Volume of C= 20 cm³

Comparing the volumes, we find that Object C has the least volume, with 20 cm³.

Therefore, Object C has the smallest volume among Objects A, B, and C.

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Answer:

CH(CH3)2C2H5 or C5H12

Explanation:

Methyl butane or isopentane is an hydrocarbon or an alkane hydrocarbon with the formula C5H12. It has five carbons and twelve hydrogens. It is volatile and highly flammable. It has high boiling point and it can boil away at room temperature on a noon day. It is use as refrigerants. It can easily vanishes to the atmosphere when exposed

Answer: In the reaction carbonic acid and decomposes form's a  water and carbon dioxide gas. Hence this is the an example of a decomposition reaction.

Explanation:

Answer:

(carbon dioxide → carbon + oxygen. (carbon dioxide + carbon → oxygen.

Explanation:

I'm not really sure if this is the answer

Answer:

Solubility

Explanation:

If its not that the answer is Dissolvable.... you didn't give a word bank.

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Answer:

94.4g/mol is molar mass of the unknown

Explanation:

Based on the freezing point depression equation:

ΔT = Kf*m*i

Where ΔT is the depression in freezing point (1.87°C)

Kf is freezing point depression constant of water (1.86°Ckg/mol)

And i is Van't Hoff factor (1 for nonelectrolyte solutes)

Replacing:

1.87°C = 1.86°CKg/mol*m*i

1.005mol/kg solvent = m

Using the mass of the solvent we can find the oles of the nonelectrolyte:

1.005mol/kg solvent * 0.4764kg = 0.479moles

Molar mass is defined as the ratio between mass of a substance in grams and moles, that is:

45.2g / 0.479mol =

Answer:

2.5 moles of KOOH are produced.

Explanation:

1)Given data:

Number of moles of KOOH produced = ?

Number of moles of LiClO = 5 mol

Solution:

Chemical equation:

2LiClO +  KHSO₄     →      Li₂SO₄ + Cl₂ + KOOH

now we will compare the moles of KOOH and LiClO.

                 LiClO          :          KOOH

                    2              :              1

                   5               :             1/2×5 = 2.5

2.5 moles of KOOH are produced.

Answer:

ionic solids

Explanation:

Ionic solids are a regular pattern of cations and anions that arrange themselves into a continuous solid network.

NaCl is composed of sodium ions and chloride ions that are held together by Coulumbic attractive forces to form a large crystal structure.

Such ionic solids have a very high melting point and do not conduct electricity in the sold state. However, the molten substance or a solution of the substance conducts electricity.

Answer:

For example, when we bake a cake, it's a result of a mixture of eggs, flour, sugar, and other ingredients.  Any time two or more items are combined, a mixture is formed. Sometimes, the different parts of a mixture can be separated into individual entities. Other times, they're married for as long as they exist.

Explanation:

Answer:

plants

Explanation:

Answer:

Sum of their partial pressures

Explanation:

If two gases are present in a container, the total pressure in the container is equal to the sum of their partial pressures.

This solution is based on the Dalton's Law of Partial Pressures.

Dalton's Law of Partial Pressure states that "the total pressure of a mixture of gases is equal to the sum of the partial pressures of the constituent gases".

A partial pressure is the pressure a gas would exert if it alone occupied the volume of the gas mixture.

Answer:

0.091

Explanation:

just took test on edg

Answer:

0.091

Explanation:

correct on edge 2021 unit test

Answer:

The answer is 105.98844.

Explanation:

We assume you are converting between grams Na2CO3 and mole. You can view more details on each measurement unit: molecular weight of Na2CO3 or mol This compound is also known as Sodium Carbonate. The SI base unit for amount of substance is the mole.

Considering the definition of molar mass, 2.5 moles are in 265 grams of Na₂CO₃.

But first you have to know that molar mass is the mass of one mole of a substance, which can be an element or a compound.

In a compound the molar mass is equal to the sum of the weight or atomic mass of its atoms multiplied by their quantity.

In this case, the atomic mass of the elements of the compound are:

Then the atomic mass of the compound Na₂CO₃ is:

Na₂CO₃= 2× 23 g/mole + 12 g/mole + 3×16 g/mole

Na₂CO₃= 106 g/mole

Then you can apply the following rule of three: if by definition of molar mass 106 grams of the compound are contained in 1 mole, 265 grams are contained in how many moles?

[tex]amount of moles=\frac{265 gramsx1 mole}{106 grams}[/tex]

amount of moles= 2.5 moles

In summary, 2.5 moles are in 265 grams of Na₂CO₃.

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