What does a group of atoms joined by chemical bonds create?
•A molecule
O A compound
O A fission reaction
O A fusion reaction

Answer:

True

Explanation:

The oil drop experiment was carried out by Robert Millikan and Harvey Fletcher in 1909 to determine the charge of an electron. By balancing downward gravitation force with upward drag and electric force, they suspended small charged droplets of oil between two metal electrodes.

The charge over an oil droplet was often an integral value of e, was determined by changing the intensity of the electric field.

So, the given statement is true

Answer:

C₂ = 50 mg/L

C₃ = 42.5 mg/L

Explanation:

To do this, we just need to use the following expression:

C₁V₁ = C₂V₂     (1)

Where:

C₁: Original concentration of the Iron solution (mg/L)

V₁: aliquot of the iron solution (mL or L)

C₂: Concentration of the iron after beind dilluted (mg/L)

V₂: Volume of the flask that's being used.

Using the above expression, we just solve for C₂:

C₂ = C₁V₁ / V₂   (2)

We have the required volumes, but we do not have the concentration of the iron solution (C₁). To determine this, we use the initial flask of 100 mL and the mass of the iron:

C₁ = 25 mg / 0.1 L = 250 mg/L

With this value, we can replace in (2) to get the concentration on each flask.

Flask 1:

We have an aliquot of 20 mL, and it was dilluted to 100 mL, the concentration would be:

C₂ = 250 mg/L * (20/100)

Flask 2:

We have an aliquot of 17 mL dilluted to 100 mL so:

C₃ = 250 * (17/100)

Hope this helps

The concentration of iron in mg/L in each of the two flasks is 50 mg/l and 42.5 mg/L respectively.

The initial concentration of iron in the sample is obtained as follows:

A vitamin tablet containing 25 mg of iron is dissolved in 6M HCl and then made up to 100 mL in a 100 mL volumetric flask with DI water.

Concentration of iron in the solution = 25 mg/ 100 mL

Converting to mg/L; 1 L = 1000 mL, then 100 mL = 1000 * 1 L/ 1000 mL = 0.1 L

Concentration of iron in the solution in mg/L = 25 mg / 0.1 L = 250 mg/L

Then 20 mL and 17 mL of this solution were pipetted into separate 100 mL volumetric flasks and each of these was brought up to 100 mL volume by diluting with DI water to the mark.

Using the dilution formula C₁V₁ = C₂V₂ to determine the concentration of iron in each of these flasks:

C₁ = initial concentration; V₁ = initial volume

C₂ = final concentration; V₂ = final volume

Flask 1:

C₁ = 250 mg/L, V₁ = 20 mL, C₂ = ?, V₂ = 100 mL

C₂ = C₁V₁ / V₂

C₂ = 250 * 20 / 100

C₂ = 50 mg/L

Flask 2:

C₁ = 250 mg/L, V₁ = 17 mL, C₂ = ?, V₂ = 100 mL

C₂ = C₁V₁ / V₂

C₂ = 250 * 17 / 100

C₂ = 42.5 mg/L

Therefore, the concentration of iron in mg/L in each of the two flasks is 50 mg/l and 42.5 mg/L respectively.

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(2)(½^(15/3)) = 0.0625 (5 half-lives) 102.4 grams order

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Explanation:

beryllium, calcium, strontium, barium, and radium; they are in the same group of table.

Answer:

Both Beryllium and Calcium have 2 valence electrons, i.e. in ther electronic configuration there are 2 electrons remaining in the outermost shell.  Thus their valencies are also 2.

Electronic Configurations:

Beryllium (4) : - [2, 2]

Calcium  (20) : [2, 8, 8, 2]

Hope it helps

Thank you for the question

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a. both are very reactive

b. both react readily with elements in group 1

c. both rarely combine with other elements

d. both are rare metals

(As per the suggestion of bvbfanforeverap5j54d)

3.2 g KClO3

Explanation:

1.1 g C12H22O11 × (1 mol C12H22O11/342.3 g C12H22O11)

= 0.0032 mol C12H22O11

0.0032 mol C12H22O11 × (8 mol KClO3/1 mol C12H22O11)

= 0.026 mol KClO3

Therefore, the minimum amount of KClO3 needed is

0.026 mol KClO3 × (122.55 g KClO3/1 mol KClO3)

= 3.2 g KClO3

Answer:

c. just like in xray machines

Explanation:

Radiation is the energy that contains electric and magnetic fields. They are the particles or the waves that are emitted from the atom. Thus, option B is correct.

Radiations are the energy or the waves transmitted in a medium or space due to the excitement of the atomic electronic transition. They are caused due to emission and removal of the electron from the atom's inner shell.

They are used in various fields of science including health and medicine where they are used to treat cancerous and tumor cells by killing the abnormal cells or slowing their growth.

Also, they are harmful as they act as mutagens that can alter the genetic material of the organism and can posses a dangerous threat to health.

Therefore, radiations are the waves emitted from atoms.

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Answer:

2 NaI (aq) + Br2 (aq) → 2 NaBr (aq) + I2 (s)

This is an oxidation-reduction (redox) reaction:

2 Br0 + 2 e- → 2 Br-I

(reduction)

2 I-I - 2 e- → 2 I0

(oxidation)

Answer:

building amino acids in proteins

Explanation:

Answer:

1. 80.9 g of CH₃OH

2. CO

3. 5.14moles

Explanation:

The reaction is:

CO  +  2H₂  →  CH₃OH

First place, we determine the moles of each reactant.

70.8 g . 1mol/ 28g = 2.53 moles of CO

20.4 g . 1mol / 2g = 10.2 moles of H₂

There is too much hydrogen, so the limiting reactant might be the carbon monoxide.

2 moles of H₂ react to 1 mol of CO

Then, 10.2 moles of H₂ may react to (10.2 . 1) /2 = 5.1 moles

We don't have enough CO, so it's ok that CO is the limiting. (We have 2.53 moles, we need 5.1 moles)

In the other hand, hydrogen is the excess reactant.

1 mol of CO react to 2 moles of hydrogen

2.53 moles may react to (2.53 . 2) /1  =5.06 moles

We have 10.2 moles, and we need 5.06 moles. Then (10.2 - 5.06) = 5.14 moles remains after the reaction goes complete.

Now that we know the limiting reactant, we can determine the grams of produced methanol. Ratio is 1:1

1 mol of CO produces 1 mol of CH₃OH

2.53 moles of CO must produce 2.53 moles of CH₃OH

We convert moles to mass: 2.53 mol . 32 g/mol = 80.9 g

Answer:

D) Ba(s) + 2 HCl(aq) → BaCl2(aq) + H2(g)

Explanation:

In a redox reaction, One atom is gaining electrons (Reduction) whereas other is loosing electrons (Oxidation). In the reactions:

A) HBr(aq) + NaOH(aq) → NaBr(aq) + H2O(l)

As sodium is always +1 and Br always -1, this is not a redox reaction.

B) NaI(aq) + AgNO3(aq) → AgI(s) + NaNO3(aq)

Sodium is always +1 and nitrate ion is -1. This is not a redox reaction

C) Pb(C2H3O2)2(aq) + 2 LiBr(aq) → PbBr2(s) + 2 LiC2H3O2(aq)

Acetate ion, C2H3O2 is -1 as Br is -1, lithium is +1 and Pb +2, This is not a redox reactoin

Barium is 0 as Ba(s) but +1 as BaCl2. Is oxidizing

Hydrogen is +1 as HCl but 0 as H2. Is reducting.

This reaction is an oxidation-reduction reaction

Answer:

Option 2

Explanation:

When surface lakes of glacier meltwater overflow into channels and pour down moulins (vertical shafts or tunnels in the ice), the water typically flows into the base of the glacier and can cause the glacier to melt more rapidly. This process is known as "moulin drainage," and it can be detrimental to the glacier because it can cause the glacier to lose mass more quickly.

Losing mass through moulin drainage can cause a glacier to retreat or shrink in size, which can have a number of impacts on the surrounding environment. For example, if a glacier is a primary source of water for a region, its retreat could lead to water shortages. In addition, the loss of a glacier can affect the local ecosystem and wildlife, and it can contribute to sea level rise if the glacier is located near the coast.

Answer:

Packed inside the nucleus of every human cell are nearly 6 feet of DNA, which is divided into 46 individual molecules, one for each chromosome and each about 1.5 inches long. Packing all this material into a microscopic cell nucleus is an extraordinary feat of packaging.

Explanation:

Packed inside the nucleus of every human cell are nearly 6 feet of DNA, which is divided into 46 individual molecules, one for each chromosome and each about 1.5 inches long. Packing all this material into a microscopic cell nucleus is an extraordinary feat of packaging. For DNA to function, it can't be crammed into the nucleus like a ball of string. Instead, it is combined with proteins and organized into a precise, compact structure, a dense string-like fiber called chromatin.

(hope this helps can i plz have brainlist :D hehe)

The allowed concentration of Cl in water is 250 ppm. Then the equivalent concentration in molarity is 0.007 molar.

Molarity is a common term used to express the concentration of a solution. It is the ratio of the number of moles of solute to the volume of solution in liters. Molarity is a temperature dependent measurement.

Parts per million is another term of concentration have the formula as written below:

ppm = ws/W × 10⁶

Where, ws is the weight of solute and W be the weight of solution in grams.

1 molar = 35500 ppm

therefore, 250 ppm = 250 ppm × 1M /35500 ppm  = 0.007 M.

Hence, the molarity of the salt solution will with the maximum  allowed concentration will be 0.007 M.

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Answer: A 2.1

Explanation:

Answer:0.226 gram

Explanation:you can get the answer in two steps calculate 3.40 . 10^22 atoms =

Answer:

4.2 × 10²² ÷ 6.022× 10²³

4.2 × 10²² equals 0.069 moles (approx)

weight of 1 mole of iron = 56g

therefore, 0.069 moles = 56 × 0.069 = 3.9 g

Sorry for lazy work.. :P

Answer: The given demonstration does not support Boyle's Law.

Explanation:

According to Boyle's law, at constant temperature the pressure of an ideal gas is inversely proportional to the volume of gas.

[tex]P \propto \frac{1}{V}[/tex]

Therefore, an increase in volume of gas will lead to a decrease in pressure and vice-versa.

Now, according to the given data of volumes there is occurring an increase on moving from final volume 1 to final volume 3. This means that pressure is decreasing.

As a result, if a balloon was squeezed or compressed then it would get smaller. But in the given demonstration pressure is not given.

Thus, we can conclude that the given demonstration does not support Boyle's Law.

Answer:

13.96

Explanation:

sorry, too lazy to give the explanation, hopefully someone else will come along and give the proper explanation

Answer: 13.96 liters

Answer:

fossil fuels

Explanation:

Well I had some topics on this stuff last quarter in science and from what I can remember it should be fossil fuels I think that fossil fuels are technically renewable but they are considered non-renewable since they are either in small supplies, are hard to obtain or take a long time to form.

Answer:

6 atoms of oxygen are included.

Explanation:

Saw a similar answer

Also

Have  a great day :D

Answer:

6 atoms are included :)

Explanation:

1 molecule of glucose contains 6 atoms

Answer:

1) (5 moles of calcium bromide) x 2 / 1 = 10 moles

2) (2.00 moles of calcium bromide) = 2.00 moles of calcium sulfate

so (2.00) x (136.1 g/mol) = 272.2 g

3) (845 grams of calcium sulfate) /  136.14 g/mol = 6.21 moles

6.21 moles of calcium sulfate = 6.21 moles of calcium bromide

(6.21 moles of calcium bromide) x 199.89 g/mol = 1241.32 g

Word equation: sulfuric acid + sulfur -> sulfur dioxide + water

Chemical equation: H2SO4 + S -> SO2 + H2O

Answer:

Word equation: Sulfuric acid + Sulfur → Sulfur Dioxide + Water

Chemical equation: H2SO4 + S → SO2 + H2O

Explanation:

Answer:

The Law of Conservation of Matter states that in a chemical reaction, matter is not created or destroyed. However, it is possible for the mass of a substance to change during a chemical reaction, as you observed.

When a substance burns, it reacts with oxygen in the air to form new compounds. For example, when wood burns, it reacts with oxygen to form water and carbon dioxide. The mass of the wood plus the mass of the oxygen is equal to the mass of the water and carbon dioxide produced.

In this case, the extra mass that you observed came from the oxygen that reacted with the wood. Oxygen has mass, and when it reacts with the wood, the mass of the resulting compounds is greater than the mass of the starting materials.

It's important to note that energy is not a form of matter, and therefore has no mass. However, energy can be converted into matter and vice versa, according to the famous equation E=mc^2, where E is energy, m is mass, and c is the speed of light. This equation demonstrates that mass and energy are fundamentally connected and can be converted into each other under certain conditions.

Explanation:

A thorough understanding of clothing and textiles will enable one to evaluate standards and product brands intelligently. It will also help one develop the capacity to recognize fabric quality, which will help one understand the best applications for the various qualities.

Understanding why some fabrics are more durable and so more suited for particular uses comes from studying textiles. It permits one to comprehend the rationale behind why particular materials generate cool-looking clothing in addition to creating the sense of coolness when used as décor. A thorough understanding of clothing and textiles will enable one to evaluate standards and product brands intelligently.

It will also help one develop the capacity to recognize fabric quality, which will help one understand the best applications for the various qualities. Although clothes don't necessarily make a person, they certainly help to develop a positive personality and a sense of self-assurance. Housewives should therefore be familiar with clothing and textiles to obtain the best out of it.

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The number of moles of the ideal gas is 0.12 moles. Option A

In the context of the problem that we have here, we are looking at the ideal  gas equation. When we look at the idea gas equation, we can tell that we would have the pressure of the gas, the volume of the gas as well as the temperature of the gas in view as is the case that we have here.

Thus, the idea that we are asked to pass across in the question is that we should be able to find out the number of moles that we have in the compound that have the variables that have been listed here.

Pressure (P) =  1 atm

Volume (V) = 1 L

Temperature (T) = 1 K

Number of moles (n) = ?

Using;

PV = nRT

n = PV/RT

n = 1 * 1/0.082 * 1

n = 0.12 moles

The moles of the gas is 0.12 moles.

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Answer:

There is a pawpaw here that is not producing any fruit.. so I will take a pollen grains from another pawpaw and pollinate it..

Answer:

develops,blossoms are synonyms