Ecology is defunded as the environment study of

Mendeleev left gaps in the periodic table to place elements not known at that time. By looking at the chemical properties and physical properties of the elements next to a gap, he predicted the properties of these undiscovered elements.

Thus we can conclude that, the chemical and physical properties of the elements next to the gap, he was able to predict gallium and germanium.

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In 1871, the atomic masses and other chemical characteristics of gallium, germanium, and scandium were unknown, but Mendeleev provided slots for each and made predictions about them.

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Answer:

B. Cutting the supplies of oxygen

To determine the mass of the piece of lead, we can use the formula q = m х c х ΔT Where q is the heat energy, m is the mass, c is the specific heat capacity, and ΔT is the change in temperature.

Given:

q = -78.00 J (negative sign indicates heat loss)

ΔT = -9 °C (negative sign indicates decrease in temperature)

c = 0.130 J/goC (specific heat capacity of lead)

Plugging in the values into the formula:

-78.00 J = m * (0.130 J/goC) * (-9 oC)

Simplifying:

-78.00 J = -1.17 m

Dividing both sides by -1.17:

m = 78.00 J / 1.17 = 66.67 g

Therefore, the mass of the piece of lead is approximately 66.67 grams.

The specific heat capacity (c) represents the amount of heat energy required to raise the temperature of one gram of a substance by one degree Celsius. In this case, the specific heat capacity of lead is given as 0.130 J/goC. By using this value and the equation above, we can calculate the mass of the lead piece based on the given heat loss and temperature change.

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Answer:

false

Explanation:

first of all;-energy lead to an indotermic reaction.

indotermic is a reaction that absorbs energy \

*it has positive enthalpy of reaction

*Heat content of product is greater than that of reactant

*Heat is added to reactant side

example;- CO^2+2H^2+891kj --------- CH4 +2O2

Due to their complete oxidation of one another, the beginning moles of the unknown acid (HA) and the final moles of the known base (NaOH) are equal.

What is oxidation, and give a case?

Summary. An element combining with oxygen is referred to as an oxidation in scientific terminology. For instance, the chemical reaction between oxygen and magnesium metal produces magnesium oxide during the oxidation of magnesium.

In order to describe a substance's reaction with oxygen, Antoine Lavoisier coined the term "oxidation." Later, when it was understood that the substance loses electrons when it is oxidized, the definition was expanded to encompass all processes in which electrons are destroyed, regardless of whether oxygen is present.

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The mass of potassium chlorate is 0.3439 to generate 114.0 L  \(O_{2}\) at 0.720 atm and 291K

The decomposition of potassium chlorate is represented as

\(2KClO_{3} (s) - > 2KCl(s) + 3O_{2} (g)\)

Given, Volume = 114.0 L

pressure = 0.720 atm

temperature = 291 K

According to the Ideal gas Equation

Pv = nRT

\(n=\frac{Pv}{RT}\)

\(n=\frac{0.720*114.0}{0.82*291}\)

n= 0.3439

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The equilibrium constant, Kp, for the reaction cannot be determined without knowing the equilibrium pressures of gases B and C in addition to the initial and equilibrium pressure of gas A.



To calculate the value of Kp, which is the equilibrium constant in terms of partial pressures, we need to use the given equilibrium pressures and the stoichiometric coefficients of the balanced equation.The equilibrium constant expression for the reaction is Kp = (P(B) * P(C)^2) / (P(A)^2), where P(A), P(B), and P(C) are the partial pressures of gases A, B, and C, respectively.

Given that the initial pressure of A is PA = 240 mmHg and the equilibrium pressure of A is PA = 55 mmHg, we can substitute these values into the Kp expression.Kp = (P(B) * P(C)^2) / (P(A)^2) = (55 * P(B) * P(C)^2) / (240^2)

To solve for Kp, we need additional information about the equilibrium pressures of B and C. Without that information, we cannot determine the exact value of Kp.

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Answer:

Photoautotrophs

Explanation:

I think you mean "autotroph"

The answer is photoautotrophs. they use sunlight to make their food

Don't forget to rate the answer for others

Answer:

Explanation:

As the redeposited minerals build up after countless water drops, a stalactite is formed. If the water that drops to the floor of the cave still has some dissolved calcite in it, it can deposit more dissolved calcite there, forming a stalagmite.

Answer:

yes jrs true

Explanation:

In some ways, sparks are harmful. So, the statement e is not true.

When an ionized, electrically conductive channel is formed through a typically insulating substance by a sufficiently strong electric field, it results in a sudden electrical discharge known as an electric spark.

Here,

Sparks are the sudden electric discharges; therefore, we can say that they are capable of causing damage to the sensitive electronic devices.

Also, a small, sudden ignition spark created in grain elevators can eventually cause mild explosions.

In an operating room, sparks can start an explosion of anesthetic gas.

Heart pacemakers can be harmed by sparks.

So we can say that sparks are capable of causing many types of damages. So, it is dangerous in someway.

Hence,

In some ways, sparks are harmful. So, the statement e is not true.

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Answer:

i believe its gas sorry if i am wrong

Explanation:

Answer: d. Compounds made by bonding of atoms of known elements.

Explanation:

Viruses are said to be so numerous that they vastly outnumber the number of stars in the universe. Viruses are quite small and are not technically alive until they get into a living cell.

Viruses are made up of compounds like everything else but just because a virus has not been discovered does not mean that it is made of unknown material. Every natural element available has already been discovered so any new virus is made of compounds of known elements.

The enthalpy of the reaction is 14 J/mol.

The enthalpy of a reaction (ΔH) is the amount of energy transferred between a system and its surroundings during a chemical reaction at constant pressure, measured in joules per mole (J/mol). This value is important because it can tell us whether a reaction is exothermic or endothermic, as well as give us information about the strength of chemical bonds within the reactants and products.To calculate the enthalpy of a reaction, we need to know the amount of energy released or absorbed (Q) and the number of moles of the compound involved in the reaction (n). We can use the equation:
ΔH = Q/n
Given that 6 moles of a compound produce 84 J of energy, we can calculate the enthalpy of the reaction as follows:
ΔH = Q/n
ΔH = 84 J / 6 mol
ΔH = 14 J/mol
This means that for every mole of the compound involved in the reaction, 14 J of energy is transferred between the system and the surroundings. Since the value is positive, we can conclude that the reaction is endothermic, meaning that it requires an input of energy to occur.It is worth noting that the enthalpy of a reaction can depend on a number of factors, such as temperature, pressure, and the specific conditions under which the reaction occurs. As such, it is important to take these factors into account when calculating or predicting enthalpy values.

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Answer:

the zinc strip begins to darken. If left in the solution for a longer period of time, the zinc will gradually decay due to oxidation to zinc ions.

Explanation:

19.7 litre volume of carbon dioxide gas at 22.0o C and 102 kPa can be collected over water.

Vapour pressure is a measure of the tendency of a material to change into the gaseous or vapour state, and it increases with temperature.

Moles of Butane = mass in grams / molar mass = 11.6 / 58.12 = 0.2

Volume of \(O_2\) (V) = 40 liter

Temperature (T) = 22°C = 22 + 273 = 295 K

Pressure (P) = 102 kPa = 102 / 101.325 = 1.007 atm

Moles of \(O_2\) (n) can be calculated by ideal gas equation.

PV = nRT

n = 1.007 40 ÷ 0.0821 295 = 1.663

Balanced chemical reaction;

2\(C_4H_10\) + 13\(O_2\) ---> 8\(CO_2\) + 10\(H_2O\)

From reaction;

13 moles \(O_2\) require 2 moles \(C_4H_10\)

So, 1.663 moles \(O_2\) will require = 2 x 1.663 ÷13 = 0.256 moles of \(C_4H_10\)

Thus \(C_4H_10\) is a limiting reagent. So it will drive the yield of \(CO_2\).

Moles of \(CO_2\) produced = (8/2) 0.2 = 0.8 moles

Pressure of \(CO_2\) (P) = 102 - 2.24 = 99.76 kPa = 99.76  ÷ 101.325 = 0.985 atm

Applying the ideal gas equation for \(CO_2\),

PV = nRT

0.985 V = 0.8 0.0821 x 295

V = 19.7 liter

The volume of \(CO_2\) produced = 19.7 liter.

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Dalton says atoms of different factors differ in size and mass, while the cutting-edge theory says they range in common mass.

The subsequent postulates are proposed by John Dalton: All count number is manufactured from very tiny debris called atoms. Atoms are indivisible particles, which can't be created or destroyed in a chemical reaction. Atoms of a given detail are identical in mass and chemical houses.

The matter is made of indivisible debris referred to as atoms. The homes of all the atoms of a given detail are the same such as mass. this may additionally be said as all the atoms of detail have same mass at the same time as the atoms of various elements have exclusive loads.

This regulation explains that the sum of all partial pressures of gas in a combination should same as the barometric pressure. it is an especially essential calculation for oxygen to determine the pressure of gas pushing into the alveoli and consequently into the circulating blood.

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Answer:

2 electrons

Explanation:

Answer:

n energy-carrying molecule found in all living things' cells. ATP absorbs chemical energy from the breakdown of food molecules and uses it to power other cellular processes.

Explanation:

Hope it helps

ATP is a crucial energy molecule in cells, providing energy for various cellular processes.

ATP, or adenosine triphosphate, is often referred to as the "energy currency" of the cell. It plays a vital role in cellular metabolism by providing energy for various processes. ATP is composed of adenosine and three phosphate groups. The energy stored in ATP is released when the terminal phosphate group is hydrolyzed, forming ADP (adenosine diphosphate) and inorganic phosphate (Pi).

The role of ATP in a cell is multifaceted. Firstly, ATP powers cellular work by providing the energy needed for chemical reactions, such as biosynthesis, active transport, and muscle contraction. It acts as an immediate source of energy that can be rapidly used by the cell.

Secondly, ATP participates in signal transduction and cellular communication. It can be hydrolyzed to ADP and Pi, releasing energy that can activate signaling molecules and enzymes involved in cell signaling pathways.

Furthermore, ATP is involved in maintaining cell homeostasis. It provides energy for processes like ion pumps that maintain the electrochemical gradients across the cell membrane, allowing cells to regulate their internal environment.

Overall, ATP is crucial for the functioning of cells as it serves as an energy carrier, facilitating energy transfer and powering various cellular processes essential for growth, metabolism, and cell survival.

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Answer:

4.similar properties

5.electrons are very reactive

Answer:

C are transferred from atoms of calcium to atoms of oxygen to form Ca+2 and O-2 ion

Explanation:

Calcium is a meta and Oxygen is a non metal. The bond that forms between a metal and a non metal is an ionic bond. In an ionic bond, the metal loses electrons while the non metal gains the electrons; hence there is transfer of electrons.

Calcium belongs to group 2 and oxygen needs 2 more electrons to complete it's electronic configuration.

Calcium would lose two electrons to form Ca+2 and oxygen would gain two electrons to form O-2 ion

The correct option is;

C. are transferred from atoms of calcium to atoms of oxygen to form Ca+2 and O-2 ion

Therefore, when this molecule undergoes electrophilic aromatic substitution, the electrophile will be preferentially directed to the ortho and para positions.

The molecule shown is a substituted benzene ring with two substituents, a methyl group (-CH3) and a nitro group (-NO2). In electrophilic aromatic substitution, the electrophile is attracted to the electron-rich region of the benzene ring, which is the pi-electron cloud above and below the ring.

The presence of the substituents can affect the electron density of the ring, which can change the position of electrophilic attack. Specifically, the electron-donating substituents such as -CH3 can increase the electron density of the ring, making it more reactive and directing the electrophile to positions that have lower electron density. On the other hand, electron-withdrawing substituents such as -NO2 can decrease the electron density of the ring, making it less reactive and directing the electrophile to positions that have higher electron density.

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3. Small batch scheduling is not an element of lean manufacturing.

Lean manufacturing is a production technique that primarily aims to shorten response times from suppliers and consumers as well as times spent in the production system. It is an approach that emphasizes avoiding waste in production systems while also boosting productivity. 

Seven elements of lean manufacturing are given below:

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The sample of helium gas must be cooled to approximately -220°C to reduce its volume from 5.9 L to 0.2 L at constant pressure.

According to the ideal gas law, the relationship between the volume (V), temperature (T), and pressure (P) of a gas can be expressed as PV = nRT, where n is the number of moles of the gas and R is the ideal gas constant. In this case, the pressure is constant, so we can simplify the equation to V/T = constant.

To find the final temperature required to reduce the volume from 5.9 L to 0.2 L, we can set up the following ratio:

(V1 / T1) = (V2 / T2)

Where V1 is the initial volume (5.9 L), T1 is the initial temperature (119°C + 273.15 = 392.15 K), V2 is the final volume (0.2 L), and T2 is the final temperature that we need to find.

Rearranging the equation, we have:

T2 = (V2 / V1) * T1

= (0.2 L / 5.9 L) * 392.15 K

≈ 13.28 K

Converting 13.28 K back to Celsius, we get:

T2 ≈ -259.87°C

Therefore, the sample of helium gas must be cooled to approximately -220°C (or -259.87°C) to reduce its volume from 5.9 L to 0.2 L at constant pressure.

The question should be:

To what temperature must a sample of helium gas be cooled from 119°C to reduce its volume from 5.9 L to 0.2 L at constant pressure?

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Answer:

It can mean "boardwalk" or a "board of a school."

~Mia Sedillo~

The reason why you could see the AgNO3 diffusing out from the center well, but not the NaCl diffusing from the peripheral wells is due to a difference in their respective diffusion rates.

AgNO3 has a higher diffusion rate compared to NaCl due to the differences in their molecular weights and structure. Additionally, the concentration gradient of AgNO3 was higher in the center well compared to the peripheral wells, which led to a more visible diffusion. On the other hand, NaCl had a lower concentration gradient and a slower diffusion rate, resulting in a less visible diffusion. Thus, the difference in diffusion rates and concentration gradients accounts for the varying visibility of the two substances.

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Notice that nitrogen is less abundant than either carbon or oxygen. this is an example of the more general observation that the abundances of these three elements follow a general pattern in which even-numbered elements are more common than the odd-numbered elements.

Natural abundance  refers to the abundance of isotopes of a chemical element that are naturally found on a planet. The relative atomic mass a weighted average, weighted by mole-fraction abundance figures of these isotopes is the atomic weight listed for the element in the periodic table.

Elements with even atomic numbers are more abundant than the elements with odd atomic numbers that come between them. Carbon is atomic number 6, nitrogen is atomic number 7, and oxygen is atomic number 8. The abundances of these three elements follow a general pattern in which even-numbered elements are more common than the odd-numbered elements that come between them.

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