What observations led to the periodic law? what observations led to the periodic law? observation that certain elements possess such property as radioactivity observation that the all halogen elements have similar properties observation that the all metals have similar properties observation that the properties of elements recur and certain elements have similar properties?
The periodic law was derived from the observation of recurring similar properties among elements when arranged by atomic mass, which then shifted to atomic number. This led to the development of the modern periodic table where elements are grouped based on their properties, as demonstrated by groups of elements like the halogens exhibiting closely related characteristics.
Explanation:The observations that led to the periodic law were predicated on the identification of patterns in the properties of elements when arranged by increasing atomic mass, which was later refined to atomic number. Early chemists noticed that elements with similar properties occurred at regular intervals, a concept known as periodicity. Dmitri Mendeleev, in particular, played a pivotal role, noting the regular occurrence of properties and organizing elements into a table accordingly, even leaving gaps for then-undiscovered elements, predicting their existence and properties. His work was critical in developing the modern periodic table, where elements are positioned in order of increasing atomic number, and housed in groups and periods where elements in the same group exhibit similar chemical properties.
Examples confirming periodic law include the observation that all halogen elements in group 17 show similar properties, such as being non-metals and forming salts with metals. Additionally, the observation that all metals display metallic characteristics and parallel reactivity patterns supported the formulation of the periodic table. Moreover, advancements like the discovery of radioactivity, while not a direct observation leading to the periodic law, provided further insight into the atomic structure and properties of elements.
how many milliliters of a .89 M solution of HCl is needed to have 1.3 mole of HCl?
The coase theorem will will breakdown when ____________. (select all that apply)
A solution containing a mixture of metal cations was treated with dilute hcl and a precipitate formed. the solution was filtered and h2s was bubbled through the acidic solution. a precipitate again formed and was filtered off. then, the ph was raised to about 8 and h2s was again bubbled through the solution. this time, no precipitate formed. finally, the solution was treated with a sodium carbonate solution, which resulted in formation of a precipitate. which metal ions were definitely present, which were definitely absent, and which may or may not have been present in the original mixture?
Part c how long does it take to raise the temperature of the air in a good-sized living room (3.00m×5.00m×8.00m) by 10.0∘c? note that the specific heat of air is 1006 j/(kg⋅∘c) and the density of air is 1.20kg/m3.
To find out how long it takes to heat a room, calculate the mass of air using room volume and air density, then use the heat equation with the specific heat of air. The missing piece is the heater's power, which is essential for calculating the exact time.
Explanation:To calculate how long it takes to raise the temperature of the air in a good-sized living room (3.00m×5.00m×8.00m) by 10.0°C, given that the specific heat of air is 1006 J/(kg·°C) and the density of air is 1.20kg/m3, we firstly need to calculate the volume of the room. The volume is obtained by multiplying the room's dimensions (V = length × width × height), which is 120 m3. Using the density of air, we find the mass of the air in the room (m = density × volume), resulting in 144 kg of air. Next, we apply the formula for heat (Q = mcΔT) to determine the amount of energy required to heat the air, where ΔT is the temperature change. With the given specific heat capacity (c) and the desired temperature increase (ΔT = 10°C), we find Q. Unfortunately, without the power (wattage) of the heating device, we can't directly calculate the time (t) required for the temperature increase. However, the initial steps show how to prepare for such a calculation once the heating power is known.
What information can be gained from running a gas chromatogram?
Of the molecules below, the bond in __________ is the most polar. hbr hi hcl hf
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Which characteristic of life is demonstrated when human skin heals after it has been cut?
A.
acquiring energy
B.
reproducing
C.
maintaining structure
D.
camouflage
Using MO theory, predict which of the following species has the longest bond and which the strongest bond, respectively: O2, O2−, O22−
MO theory i.e. molecular orbital theory is used to determine the structure of molecule and explains the bonding present in the molecule by using linear combination of atomic orbitals. The bond length in the given species of oxygen can be identify on the basis of the positions of the electrons in this theory.
The mathematical expression of bond order is given by:
[tex]Bond order = \frac{1}{2}\times (electrons in bonding Molecular orbitals - electrons in anti-bonding Molecular orbitals)[/tex]
The molecular diagrams are shown in the image.
Now, calculate bond orders:
For, [tex]O_{2}^{2-}[/tex]: It consist of 10 bonding electrons and 8 anti-bonding electrons.
Bond order = [tex] \frac{1}{2}\times (10 - 8)[/tex]
= 1
For, [tex]O_{2}[/tex]: It consist of 10 bonding electrons and 6 anti-bonding electrons.
Bond order = [tex] \frac{1}{2}\times (10 - 6)[/tex]
= 2
For, [tex]O_{2}^{-}[/tex]: It consist of 10 bonding electrons and 7 anti-bonding electrons.
Bond order = [tex] \frac{1}{2}\times (10 - 7)[/tex]
= 1.5
Since, bond order is inversely proportional to bond length implies higher the bond order short will be the bond length.
Thus, order of bond length: [tex]O_{2}< O_{2}^{-}< O_{2}^{2-}[/tex]
Longest bond: [tex]O_{2}^{2-}[/tex]
Using Molecular Orbital theory, O22- has the longest bond, because it has the fewest bonding electrons. O2 has the strongest bond due to its highest bond order.
Explanation:In molecular orbital (MO) theory, the bond length is dependent on the number of bonding electrons. The more bonding electrons, the shorter the bond. Bond strength, conversely, is related to bond order - the higher the bond order, the stronger the bond. O2 has a bond order of 2, O2- has a bond order of 1.5, and O22- has a bond order of 1. Therefore:
The species with the longest bond is O22- as it has the least bonding electrons, hence longer distance between nuclei due to less attraction.The species with the strongest bond is O2, which has the highest bond order, indicating higher bond energy.Learn more about Molecular Orbital Theory here:https://brainly.com/question/31844972
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Look at the Lewis structures of the following molecules and predict their 3-D shapes according to the VSEPR theory. Part A Silane (SiH4)
The Lewis structure of silane (SiH₄) consists of a central silicon atom bonded to four hydrogen atoms. According to VSEPR theory, it has a tetrahedral geometry with no lone pairs on the central atom and bond angles near 109.5 degrees.
The student's question pertains to predicting the 3-D shapes of molecules using Valence Shell Electron Pair Repulsion (VSEPR) theory, specifically for the molecule silane (SiH₄). To predict the molecular geometry using VSEPR, we start by drawing the Lewis structure for silane, where silicon (Si) is at the center with four hydrogen atoms (H) bonded to it, each sharing a pair of electrons to complete the Si valence shell.
Following the VSEPR theory, the molecule adopts a shape that minimizes electron pair repulsions, which, in the case of silane with four bonded atoms and no lone pairs on the central atom, results in a tetrahedral geometry. The Lewis structure illustrates this with four single bonds extending from the silicon atom towards the hydrogen atoms. Any lone pairs (which silane doesn't have) would also be considered to provide a full understanding of the molecule's geometry.
Considering the application of VSEPR theory, recall that the VSEPR theory accurately predicts the tetrahedral shape for methane (CH₄), which is structurally analogous to silane (SiH₄). Therefore, we can conclude that the 3-D shape of silane will also be tetrahedral, with bond angles close to 109.5 degrees between the bonds.
Decide whether each molecule is stable or not. decide whether each molecule would be diamagnetic or paramagnetic. calculate each molecule bond order.
Predict the mass of iron (III) sulfide produced when 3.0 g of iron filings react completely with 2.5 g of yellow sulfur solid, S8(s).
The complete balanced chemical reaction to this would be:
2 Fe + 3/8 S8 --> Fe2S3
First convert mass into number of moles.
moles Fe = 3 g / (55.845 g/mol) = 0.05372 mol Fe
moles S8 = 2.5 g / (256.52 g/mol) = 0.0097458 mol S8
Then we find the limiting reactant. The limiting reactant is the one which has lower (moles/coefficient) ratio.
Fe = 0.05372 / 2 = 0.02686
S8 = 0.0097458 / (3/8) = 0.02599
So since S8 has lower ratio, therefore it is the limiting reactant so we base our calculation from it. From the reaction, we get 1 mole of Fe2S3 for every 3/8 mol of S8, therefore:
moles Fe2S3 = 0.0097458 mol S8 * (1 mole Fe2S3 / 3/8 mol S8)
moles Fe2S3 = 0.02599 mol
The molar mass of Fe2S3 is 207.9 g/mol, so the mass is:
mass Fe2S3 = 0.02599 mol * 207.9 g/mol
mass Fe2S3 = 5.4 grams
The answer is D
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Why is it important to form sparingly soluble salt in gravimetric analysis?
Suppose that your experimental formula is mg2o3. what are the implied charges on the ions in mg2o3? do these charges agree with those expected from trends in the periodic table? explain.
A. what are the implied charges on the ions in mg2o3?
Suppose that we have an element A with a charge “a+”, and element B with a charge “b-”. The chemical reaction would be:
A(a+) + B(b-) --> AbBa
So in this case, we can see that:
Mg has a charge of 3+ while O has a charge of 2-.
B. do these charges agree with those expected from trends in the periodic table
From the periodic table, we can see that Mg should only have a charge of 2+ and not 3+.
This might mean that Mg can take different oxidation states.
answer the following question by entering the numeric value with appropriate units. if the length of one side of a square is 12.0 m, what is the perimeter of the square?
If the length of one side of a square is 12.0 m, the perimeter of the square will be 48.0 meters.
What is a square?A square is a shape of geometry which have four sides and the condition for the sure that all side of it must be equal to each other in length width and height and the angles between the sides must be 90 degrees.
To calculate the perimeter the length of one side must be multiplied by 4 as squares have 4 sides with it so, 12 is multiplied by 4 and the result will be 48 meters. so, the parameter of the square will be 48 meters.
Therefore, the length of one side of a square is 12.0 m, and the perimeter of the square will be 48.0 meters.
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How many cations are there in 20.0 g of sodium phosphate?
Which characteristic of life is demonstrated when oak trees make many acorns that can become new oak trees?
Reproduction is the characteristic of life is demonstrated when oak trees make many acorns that can become new oak trees.
what are the features of oak tree ?Oak trees has the majestic branches consist of huge areas, having notable characteristics, its height which reach from heights of up to 100 feet, and having the width of up to 150 feet.
The oak family is the largest family consist of 600 species, divided into White oak which is a dark grayish-brown color and the branches of the white oak are not twisted, produce acorns with colorings that range from light green to tan, and rich green leaves.
Red Oak tree have bright red color and the feature like recognizable thick golden hairs that grown along the underside of its leaves.
Black Oak is dark-colored trunk for which this tree is named. Another classic feature with twisted branches and root system, contoured shape of the black oak.
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To carry out a particular reaction, you determine that you need 0.0500 moles of ammonium chloride. What volume of the solution described above will you need to complete the reaction without any leftover NH4Cl?
To obtain 0.0500 moles of NH4Cl from a 1.00 M solution, we need 50.0 mL of the solution. This is calculated by dividing the moles needed by the molarity of the solution.
Explanation:To determine the volume of ammonium chloride (NH4Cl) solution needed, we first need to know the molarity of the solution. The molarity can be calculated using the formula: Molarity (M) = Moles of solute / Volume of solution (in liters).
In the given information, a 5.36-g sample of NH4Cl is added to make a solution of 0.100 L. The molar mass of NH4Cl is approximately 53.49 g/mol, so 5.36 g is about 0.100 moles. Therefore, the molarity of the NH4Cl solution is 0.100 moles / 0.100 L = 1.00 M.
If we need 0.0500 moles of NH4Cl for the reaction, we can use the molarity to calculate the needed volume: Volume = Moles / Molarity = 0.0500 moles / 1.00 M = 0.0500 L or 50.0 mL. Therefore, we need 50.0 mL of the NH4Cl solution to provide the 0.0500 moles needed for the reaction.
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To complete the reaction without any leftover NH4Cl, you will need a volume of 0.500 L or 500 mL of the solution.
Explanation:To calculate the volume of the solution needed, we can use the formula: volume (in liters) = moles / molarity. In this case, the moles of ammonium chloride is given as 0.0500. We can calculate the molarity by dividing the moles by the volume in liters. The given volume of the solution is 0.5000 L. So, the molarity will be:
Molarity = Moles / Volume = 0.0500 moles / 0.5000 L = 0.100 M
Now, we have the molarity, which is 0.100 M. To find the required volume of the solution, we can rearrange the formula: volume = moles / molarity. Substituting the given values, the volume will be:
Volume = Moles / Molarity = 0.0500 moles / 0.100 M = 0.500 L or 500 mL
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Why is the third equivalence point not observed in the titration curve for phosphoric acid?
Final answer:
The third equivalence point for phosphoric acid is not observed due to the weak acidity of HPO, resulting in an unclear definition of the pH at this point.
Explanation:
The third equivalence point for phosphoric acid (H3PO4) is not observed in the titration curve because HPO is a very weak acid, resulting in the third deprotonation step having a pH that is not well-defined.
The first two equivalence points are seen at approximately pH 4.6 and pH 9.8, corresponding to the deprotonation of H3PO4 and H2PO4-, respectively. Due to the weak acidity of HPO, the third equivalence point at pH ≈ 13 is not clearly distinguishable
Bromine, a liquid at room temperature, has a boiling point of 58°C and a melting point of –7.2°C. Bromine can be classified as a
Explanation:
A pure substance is defined as the substance that contains same type of atoms or atoms of one type of molecule.
A pure substance will always have a fixed melting and boiling point.
For example, at room temperature bromine is a liquid and its boiling point of [tex]58^{o}C[/tex] and a melting point of [tex]-7.2^{o}C[/tex].
Hence, bromine is a pure substance.
Whereas when two or more different substances are mixed together irrespective of their ratio by mass then they are known as mixtures. And, mixtures always show a range of temperature for their melting and boiling point.
Hence, bromine is not a mixture.
How are muscles and bones related?
what is the mass number of an ion that has 83 protons, 80 elections, and 126 neutrons
Considering the definition of mass number, the mass number of the ion is 209.
All atoms are made up of subatomic particles: protons and neutrons, which are part of their nucleus, and electrons, which revolve around them.
Mass Number is the integer equal to the sum of protons and neutrons present in the nucleus of an atom. This is:
Mass number = (number of protons) + (number of neutrons)
It is represented by the letter A.
In this case:
number of protons= 83 number of neutrons= 126So:
Mass number = 83 + 126
Solving:
Mass number= 209
In summary, the mass number of the ion is 209.
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brainly.com/question/11837355?referrer=searchResults brainly.com/question/1758023) A round or oval hole through a bone, which contains blood vessels and/or nerves, is called a __________.
The term for a round or oval hole through a bone that contains blood vessels and/or nerves is a 'foramen'. These are present in various bones and allow for the passage of essential elements.
Explanation:In biology, a round or oval hole through a bone that contains blood vessels and/or nerves is called a foramen. Examples include the foramen magnum in the base of the skull which allows the spinal cord to connect with the brain, and the mental foramen in the jawbone which allows nerves and blood vessels to pass. The presence of foramen in bones is vital as it allows for the passage of essential materials.
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A round or oval hole in a bone that accommodates blood vessels and/or nerves is called a foramen. An example of this is the nutrient foramen, through which an artery enters a bone to nourish it. Foramina permit the input and output of arteries and veins to the bone, and also facilitate communication for the bone tissue.
Explanation:A round or oval hole through a bone, which contains blood vessels and/or nerves, is called a foramen. For example, the nutrient foramen is a small opening in the middle of the external surface of a bone's diaphysis, through which an artery enters the bone to provide nourishment. These foramina, the plural of foramen, allow the passage of arteries and veins to and from the bone, as well as nerves, providing the necessary nourishment and communication for the bone tissue.
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Calculate the number of moles of magnesium, chlorine, and oxygen atoms in 4.50 moles of magnesium perchlorate, mg(clo4)2. express the number of moles of mg, cl, and o atoms numerically, separated by commas.
What is the ionic charge for the calcium ion in CaCO3?
A stone is dropped from the roof of a building; 2.00s after that, a second stone is thrown straight down with an initial speed of 25.0m/s, and the two stones land at the same time. how long did it take the first stone to reach the ground? how high is the building? what are the speeds of the two stones just before they hit the ground?
Final answer:
The first stone takes 2.00 seconds to reach the ground. The height of the building can be calculated using h = (1/2)gt^2. The speed of the first stone just before it hits the ground is given by v = gt.
Explanation:
Question:
A stone is dropped from the roof of a building; 2.00s after that, a second stone is thrown straight down with an initial speed of 25.0m/s, and the two stones land at the same time. How long did it take the first stone to reach the ground? How high is the building? What are the speeds of the two stones just before they hit the ground?
Answer:
For the first stone to reach the ground at the same time as the second stone, it must take 2.00 seconds. This is because both stones land at the same time, and the second stone was thrown after 2.00 seconds. The height of the building can be calculated using the equation h = (1/2)gt^2, where g is the acceleration due to gravity (9.8 m/s^2) and t is the time (2.00 seconds). The speed of the first stone just before it hits the ground is calculated using the equation v = gt, where g is the acceleration due to gravity (9.8 m/s^2) and t is the time (2.00 seconds). The speed of the second stone just before it hits the ground is given as 25.0 m/s.
Solid aluminum hydroxide reacts with a solution of hydrobromic acid. write a balanced molecular equation and a balanced net ionic equation, including the states of each species.
The balanced molecular equation for the reaction between aluminum hydroxide and hydrobromic acid is Al(OH)3 + 3HBr → AlBr3 + 3H2O, while the balanced net ionic equation is Al(OH)3 + 3H+ → Al3+ + 3H2O. This represents an acid-base neutralization reaction.
Explanation:The reaction between solid aluminum hydroxide (Al(OH)3) and hydrobromic acid (HBr) results in the formation of aluminum bromide (AlBr3) and water (H2O). The balanced molecular equation for this reaction is: Al(OH)3 (s) + 3HBr (aq) → AlBr3 (aq) + 3H2O (l).
Moving on to the balanced net ionic equation, remember that strong acids such as hydrobromic acid ionize completely in water. Therefore, we have Al(OH)3 (s) + 3H+ (aq) + 3Br- (aq) → Al3+ (aq) + 3Br- (aq) + 3H2O (l). By cancelling out the similar ions on both sides of the equation, we are left with the net ionic equation which is: Al(OH)3 (s) + 3H+ (aq) → Al3+ (aq) + 3H2O (l).
It is important to note that the (s) denotes a solid, the (aq) a species in an aqueous solution and the (l) a liquid. This chemical reaction represents a typical acid-base neutralization process, where a base (here aluminum hydroxide) reacts with an acid (hydrobromic acid) to produce a salt (aluminum bromide) and water.
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In a calorimeter, the equilibrium temperature of copper in water is determined. if the water is replaced with a liquid that has a lower specific heat, what will happen to the equilibrium temperature
Final answer:
Replacing water with a liquid with a lower specific heat in a calorimeter experiment will result in a higher final equilibrium temperature for the copper and liquid compared to if water were used.
Explanation:
When conducting an experiment in a calorimeter where a hot piece of copper is placed in a liquid to reach thermal equilibrium, the specific heat capacity of the liquid will affect the final equilibrium temperature of both substances. If the copper is submerged in a liquid with a lower specific heat than water, the liquid will reach a higher temperature than it would if water were used. This is because a liquid with a lower specific heat capacity requires less heat transfer to increase its temperature by 1°C. Accordingly, the copper would not cool down as much as it would in water because less heat is needed to warm up the liquid. Hence, the final equilibrium temperature when using a liquid with a lower specific heat will be higher than if water were used.
what elements make up molecules make up molecules of sugar
Answer:
Carbon, hydrogen and oxygen.
Explanation:
Hello,
Chemically speaking, sucrose is the molecule composing the sugar and it is shown on the attached document wherein it is seen that it is made up of carbon, hydrogen and oxygen. In addition, it is categorized as disaccharide, a molecule consisting of two monosaccharides: glucose and fructose. It is produced naturally in plants, from which table sugar is refined. It has the shown below molecular formula:
[tex]C_{12}H_{22}O_{11}[/tex]
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What is the density of an unknown substance that has a mass of 50 g and its measurements are 9.0 cm high, 10cm long, and 2 cm wide?