Answer:
if an atom gains an electron, the ion has negetive charge
Examine the given reaction. NH4NO3(s) → NH4+(aq) + NO3–(aq) ΔH° = 25.45 kJ/mol ΔS° = 108.7 J/mol·K Which of the given is correct about the ΔG° at 25 °C?
A)+4,360 J
B)−6,942 J
C)−4,360 J
D)+6,942 J
Answer:
B)−6,942 J /mol
Explanation:
At constant temperature and pressure, you cand define the change in Gibbs free energy, ΔG, as:
ΔG = ΔH - TΔS
Where ΔH is enthalpy, T absolute temperature and ΔS change in entropy.
Replacing (25°C = 273 + 25 = 298K; 25.45kJ/mol = 25450J/mol):
ΔG = ΔH - TΔS
ΔG = 25450J/mol - 298K×108.7J/molK
ΔG = -6942.6J/mol
Right solution is:
B)−6,942 J /mol Which of the following is not an antioxidant _________
1) Sodium benzoate 2) Sulphur dioxide 3) Sulphite salts 4) Citric acid
Answer: 1. Sodium Benzoate
Explanation: An anti-oxidant is a substance that can help prevent or stop the damage done by free radicals. Examples include; Sulphur Dioxide, Sulphite Salts, Citric Acid, e.t.c
Sodium benzoate is a pure preservative.
Chemical change example
Answer: burning paper
Explanation:
The paper burns in air to form smoke and ash. which makes it a chemical change.
3. How many meters above sea level is the base of your landform?
How many meters above sea level is the top of your platform?
Answer:
Base is 715 and top is 850.
Explanation:
715 meters above sea level is the base of my landform and 850 meters above sea level is the top of my platform. Base of landform from a sea level is a starting point of a city or region having same topography. This region has a specific height where it spreads we called it top of the platform. The starting point of my location is 715 meters above sea level spreads up to 850 meters of elevation.
All the simple machines make work easier to do by changing the _____ or _____ of a force. A. size; type B. work; type C. size; direction D. type; direction
Answer:
C. size; direction
Explanation:
By definition, a machine is referred to any device that makes work easier. It takes force to do work, hence, work refers to the application of force over a particular distance. A machine aims at making the work easy by changing how it is done. Simple machines, which include: levers, pulleys, inclined planes etc. all carry out the same thing, which is to make work easier, by changing the size/magnitude and direction of the applied force.
A simple machine tends to change the size of the inputted force by increasing it over a shorter distance. The machine increases the force applied better than it can be done manually e.g. a plier and nutcracker increases/changes the applied force better than it can be done with bare hands.
Also, a simple machine can achieve making work easier by changing the direction at which the force is applied. The machine applies the force on the object in an opposite direction or contrary to the way it was manually applied.
4. The mass of a silver liberty (coin) was measured three times and each measurement was made
to five digits. The mass values were 12.519 9.12.521 g, and 12.496 g. The average mass was
reported as 12.512 g.
Why is the average mass of the gold coin reported to five significant figures, even though you
had to divide by "3" to obtain the average?
Answer:
The average mass of the gold coin reported to five significant figures, even though you had to divide by "3" to obtain the average.
Explanation:
Given that,
The mass of a silver liberty was measured three times and each measurement was made to five digits.
The mass values are,
[tex]m_{1}=12.519\ g[/tex]
[tex]m_{2}=12.521\ g[/tex]
[tex]m_{3}=12.496\ g[/tex]
The average mass of the gold coin is 12.512 g.
We know that,
Significant figures :
Significant figures is explained the nonzero, leading zero and zeros between two nonzero digits.
For example,
The digits is 0.003405
In the digit, 345 = nonzero
0.00 = leading zero
The average mass of the gold coin reported to five significant figures because average mass is 12,512. All digits are nonzero.
Nonzero digit are significant.
Hence, The average mass of the gold coin reported to five significant figures, even though you had to divide by "3" to obtain the average.
why is an element considered a pure substance
Answer:
Because they cannot be separated into more then one type of substance.
Explanation:
Answer:
Elements are made of only one kind of atom. The particles can be a single atom or a molecule made of only one kind of atom. There is no physical change that can separate elements into more than one kind of substance. This makes an element a pure substance.An element is made up of only one type of atom. An element cannot be broken down into a simpler form.
Which of the following statements is true? A. Isotopes of the same element have the same number of protons and neutrons. B. Isotopes have the same physical properties as the normal atom but different chemical properties. C. Isotopes have the same chemical properties as the normal atom but different physical properties. D. If an isotope of one element has the same atomic mass as another element, they will have the same properties.
Answer:
B
Explanation:
Isotopes have the same number of protons but different number of neutrons.
The true statement is,
Isotopes have the same chemical properties as the normal atom but different physical properties.So, option C is correct one.
What is isotopes?The elements have same number of proton but different number of neutrons.Example: hydrogen, deuterium, tritiumWhy isotopes of same elements have different physical properties?The isotopes have different physical properties like freezing point , mass, melting or boiling point etc because they have different mass number .
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Os subníveis mais energéticos de um dado átomo são: ...4s2 3d10 4p5 a) indique o seu número atomico b) quantos electrões de valência apresenta esse átomo c) a que família pertence?
Answer:
A. 35
B. 7
C. halogênios
Explanation:
Aqui, para responder a essa pergunta, precisaremos conhecer o elemento particular em questão.
..... 4s ^ 2 3d ^ 10 4p ^ 5 significa que está a cinco elétrons da configuração eletrônica do último elemento na primeira camada dos metais pesados.
O último elemento da 1ª série do elemento de transição é o zinco, portanto, como está a apenas 5 elementos de distância, o átomo de que estamos falando é o átomo de Bromo de Bromo.
A. O zinco tem um número atômico 30 e como o bromo está a 5 elementos de distância, seu número atômico é 35
B. Uma vez que pertence ao grupo halogênio, tem 7 elétrons de valência como o resto da família
C. Pertence à família dos halogênios
Please be I need this quick
2. For each pair of atoms determine which can steal an electron easier (higher electronegativity),
draw a picture of Bohr's model, and explain why:
a. Oxygen and Fluorine
b. Sodium and Potassium
c. Boron and Calcium
Answer: Option (A) is the correct answer.
Explanation:
An atom who has seven valence electrons in its ground state will have the following electronic configuration in its sub shells as 2, 7.
Thus, there will be in total 9 electrons and it is known that fluorine has atomic number 9.
Whereas sodium has 2, 8, 1 electrons in its sub-shell.
Calcium has 2, 8, 8, 2 electrons in its sub-shell and oxygen has 2, 6 electrons in its sub-shell.
Thus, we can conclude that out of the given options, fluorine is the element whose atom in the ground state has seven valence electrons.
Which substance has the highest melting point? Select one: a. sugar b. Oxygen c. Diamond
Answer:
Diamonds
Explanation:
The melting point of sugar is 186C
The melting point of oxygen is -218C
The melting point of diamonds are 4078C
Therefore diamonds have the highest melting point.
You can also think of their structures, as diamonds have a covalent network structure, meaning they are really strong and have a high melting point
Oxygen has a covalent molecular structure
Sugar has a much weaker covalent network structure
Why are ionic crystals soluble in water?
A. The covalent bonds in the ionic crystal can easily reshape to bond with the water molecules, allowing it to dissolve.
B. The water slides the layers of the ionic crystal lattice so that positive charges line up with positive charges. They repel
each other and break the crystal apart.
C. Partial charges in water molecules attract the charges in the atoms of the ionic crystal, pulling the atoms off the crystal.
D. They are not. The positive and negative charges in the ionic lattice are stronger than the partial charges in the water.
Answer:
C. Partial charges in water molecules attract the charges in the atoms of the ionic crystal, pulling the atoms off the crystal.
Explanation:
Water consists of partial positive and hydrogen ions and partial negative oxygen ions. The ionic crystals also dissociate into ions when in water.These partial charges and ability of ionic compounds to dissociate in water are the main reason why ionic crystals dissolve in water.
The partial charges in the water molecules form a strong attraction towards the charges in the atoms of ionic crystals. This then pulls the atoms from the crystals and ends up in the dissolution of the ionic crystals.
A wittig reaction occurs when 4-methylbenzaldehyde and benzyltriphenylphosphonium chloride are stirred together at room temperature in the presence of sodium hydroxide base. Draw the major isomer produced by this reaction.
Answer:
See explanation
Explanation:
The wittig reaction is an organic reaction in which an aldehyde or a ketone reacts with a phosphonium ylide to give an alkene. This phoshonium ylide that participates in the reaction is usually generated insitu in the system by reaction of an alky or aryl triphenylphosphonium halide salt with a base(sodium hydroxide is mostly used).
In this particular reaction 4-methylbenzaldehyde and benzyltriphenylphosphonium chloride were reacted together in the presence of sodium hydroxide and the product with the structure shown in the answer was obtained as the major isomer produced in the reaction.
A botanist measures a plant growth at 3cm over a two week period. The information she gathers is called.
Answer:
The correct answer is quantitative data.
Explanation:
The value of data in the form of numbers of counts where each set of data exhibits a specific numerical value associated with it is termed as quantitative data. This information refers to any quantifiable knowledge, which can be used for statistical analysis and mathematical calculations so that decisions of real-life can be taken based on the mathematical outcomes. The quantitative data is used to find the solutions of the queries like how often, how much, or how many.
In the given case, a botanist measured the growth of the plant for two weeks, and the outcome came in the form of numerical value. Thus, the knowledge she collected is known as quantitative data.
The table describes how some substances were formed.
Substance
P.
Q
Description
Formed by boiling pure water
Formed by combining three hydrogen atoms to every nitrogen atom
Formed by adding 5 g of sugar to 1 L of water
Formed by compressing carbon under high pressure
R
S
Based on the given descriptions, which substance is most likely a mixture?
P
Q
R
S
Explanation:
Which is a pure substance?
1. soda
2. gasoline
3. salt water
4. carbon dioxide
carbon dioxide
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
1. compound.
2. impure substance.
3. mixture.
4. pure substance.
pure substance.
Answer:
the answer is
Explanation:
Sugar and water make a homogeneous mixture (the same proportions of its components throughout any given sample).
What is the product of the reaction of pentanoic acid with ethanol in the presence of a strong acid?
Answer:
ethylpentanoate
Explanation:
Alkanoic acids react with alkanols in the presence of mineral acids to yield an ester and water. This is the organic analogue of the inorganic neutralization reaction. The reaction his commonly called esterification. It is an acid catalysed reaction.
The reaction of pentanoic acid and ethanol in the presence of a string acid is shown below;
CH3CH2CH2CH2COOH(aq) + CH3CH2OH(aq) ----> CH3CH2CH2CH2COOCH2CH3(aq) + H2O(l)
The name of the compound formed is ethylpentanoate.
3. why are fire tornadoes rare ?
1. The Tyndall Effect is most useful for distinguishing between: *
a solute and a solvent
O a suspension and a solution
a colloid and a suspension
a colloid and a solution
Answer:
a colloid and a solution
Explanation:
When solute particles completely dissolve in a solvent, a true solution is formed. The solute particles in this case are so little that they can not be seen with naked eyes. A true solution does not scatter rays of light.
In a false solution, the solute particles are larger than the solute particles in true solutions but are not large enough to be seen with naked eyes. False solutions scatter rays of light. False solutions are also called colloids.
The major difference between a solution and a colloid is that colloids scatter light rays (Tyndall effect) while a true solution does not scatter light rays.
which statement is true about this reaction 14/7n + 1/1h ------> 15/8o
A. it is a practical source of energy on earth
B.it occurs only outside the solar system
C.its product is heavier than each of its reactants
D.it shows the critical mass of an element
Answer: answer is C
Explanation:
Its product is heavier than each of its reactants is true about this ₇N¹⁴ + ₁H¹ → ₈O¹⁵ reaction
What is Nuclear reaction ?A nuclear reaction is a reaction in which one or more than one nuclides are generate and it collides between two atomic nuclei or one atomic nucleus.
The reaction is
₇N¹⁴ + ₁H¹ → ₈O¹⁵
Now equating the mass number of both sides
14 + 1 = 15 + a
a = 0
Equating atomic number of both sides
7 + 1 = 8 + x
x = 0
Thus, we can say that its product is heavier than each of its reactants is true about this reaction
Hence, option C is correct answer.
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what’s the answer to this?
Define physical and chemical properties, provide three examples of each, discuss their reversibility, and explain the fundamental differences between them.
Answer:
Physical properties are defined as the properties which can be observed without changing its chemical composition.
For example: color, volume, and molecular weight.
Chemical properties are defined as the properties which can be observed only after changing chemical identity of the substance.
For example: reactivity, toxicity, and flammability.
The fundamental differences between physical and chemical properties are as follows:
Chemical properties are related to chemical bonds of the substance while physical properties are not.In chemical properties, chemical identity of substance changes while physical properties do not have any change.Chemical properties predict the reaction of substance while physical properties only describe the appearance of the substance.
Answer:
Chemical properties are related to chemical bonds of the substance while physical properties are not.
In chemical properties, chemical identity of substance changes while physical properties do not have any change.
Chemical properties predict the reaction of substance while physical properties only describe the appearance of the substance.
Explanation:
In the image above the ruler is measuring in centimeters. The blue cylinder falls somewhere between 2.7cm and 2.8cm according to the ruler. Since we can estimate the last digit I would say that the length of the cylinder is 2.76cm. Since I am estimating any number 2.72cm or 2.78cm could also be correct.
Why would 2.755 not be a correct measurement according to estimating the last digit?
Answer:
The answer is below
Explanation:
Resolution is the smallest unit of measurement that can be measured by a measuring instrument. Each point on the ruler is 0.1 cm and the difference between any two points, about 0.01 cm cam be measured. The minimum measurement (resolution) that can be measured by the ruler is 0.01 cm (two decimals), therefore it cannot measure up to three decimal places such as numbers like 2.755.
How many moles of potassium in 73.56g of potassium chlorate (V) (KClO 3 )?
Answer:
Approximately [tex]0.6003\; \rm mol[/tex] formula units.
Explanation:
Formula Mass of KClO₃Look up the relative atomic mass data for [tex]\rm K[/tex], [tex]\rm Cl[/tex], and [tex]\rm O[/tex] on a modern periodic table:
[tex]\rm K[/tex]: [tex]39.908[/tex].[tex]\rm Cl[/tex]: [tex]35.45[/tex].[tex]\rm O[/tex]: [tex]15.999[/tex].The relative atomic mass of an element is numerically equal to the mass (in grams) of one mole of its atoms. For example, the relative atomic mass of [tex]\rm K[/tex] is [tex]39.908[/tex]. Therefore, the mass of one mole of [tex]\rm K\![/tex] atoms should be [tex]39.908\; \rm g[/tex].
Each [tex]\rm KClO_3[/tex] "formula" unit includes one [tex]\rm K[/tex] atom, one [tex]\rm Cl[/tex] atom, and three [tex]\rm O[/tex] atoms. Therefore, one mole of [tex]\rm KClO_3\![/tex] formula units would include:
one mole of [tex]\rm K[/tex] atoms, one mole of [tex]\rm Cl[/tex] atoms, and three moles of [tex]\rm O[/tex] atoms.From the relative atomic mass of these three elements:
The mass of one mole of [tex]\rm K[/tex] atoms would be [tex]39.908\; \rm g[/tex].The mass of one mole of [tex]\rm Cl[/tex] atoms would be [tex]35.45\; \rm g[/tex].The mass of three moles of [tex]\rm O[/tex] atoms would be [tex]3 \times 15.999\; \rm g = 47.997\; \rm g[/tex].Combining these three parts should give the mass of one mole of [tex]\rm KClO_3[/tex] formula units:
[tex]\begin{aligned}& M(\mathrm{KClO_3}) \\ &= 39.908 + 35.45 + 3 \times 15.999 \\ &= 122.545\; \rm g \cdot mol^{-1}\end{aligned}[/tex].
Number of moles of KClO₃ formula units in the sampleThe formula mass of [tex]\rm KClO_3[/tex] is [tex]M(\mathrm{KClO_3}) = 122.545\; \rm g \cdot mol^{-1}[/tex], meaning that the mass of one mole of [tex]\rm KClO_3\![/tex] formula units would be [tex]122.545\; \rm g\![/tex].
The mass of this [tex]\rm KClO_3\!\![/tex] sample is [tex]m(\mathrm{KClO_3}) = 73.56\; \rm g[/tex]. The number of moles of formula [tex]\rm KClO_3\![/tex] units in this sample would be:
[tex]\begin{aligned}n(\mathrm{KClO_3}) &= \frac{m(\mathrm{KClO_3})}{M(\mathrm{KClO_3})} \\ &= \frac{73.56\; \rm g}{122.545\; \rm g \cdot mol^{-1}} \approx 0.6003\; \rm mol\end{aligned}[/tex].
To know the exact number of mole of potassium (K) in 73.56 g of potassium chlorate (v), KClO₃ do the following:
Step 1:Determination of the number of mole in 73.56 g of potassium chlorate (v), KClO₃
Mass of KClO₃ = 73.56 g
Molar mass of KClO₃ = 39 + 35.5 + (16×3)
= 39 + 35.5 + 48
= 122.5 g/mol
Mole of KClO₃ =?[tex]Mole =\frac{mass}{molar mass}\\\\Mol KClO_{3} = \frac{73.56}{122.5}[/tex]
Mole of KClO₃ = 0.6 moleStep 2:Determination of the number of mole of potassium, K in 0.6 mole (i.e 73.56 g) of KClO₃
Considering the molecular formula of potassium chlorate (v), KClO₃, we can see that:
1 mole of KClO₃ contains 1 mole of K.
Therefore, 0.6 mole of KClO₃ will also contain 0.6 mole of K.
Therefore, we can conclude that 73.56 g of KClO₃ contains 0.6 mole of potassium, K.
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differences between properties of convalent and ionic bond.
Ionic bonds will be a metal + a nonmetal, and electrons
are transferred from the metal to the nonmetal.
A covalent bond will be a nonmetal only. Nonmetals will not give up their electrons so electrons are shared.
I have also written this on the whiteboard in the image provided.
what are the efficient things needed for a village
Answer:
Those aspects which are something a village needs are specified beneath.
Explanation:
Things being equally necessary to make living simpler and therefore more enjoyable. The government has promised to continue providing basic facilities to either an unpopulated location, including such roads, drinkable water, as well as electric power. Therefore, throughout the village, certain things accessible with maximum variety and quality that have become the basic requirements for this human existence.what is the correct electron configuration for an element with five electrons in the third energy level
[tex]1s^2 2s^2 2p^6 3s^2 3p^3[/tex] is the correct electron configuration for an element with five electrons in the third energy level.
What are elements?Elements are the simplest substances which cannot be broken down using chemical methods.
The shell nearest to the nucleus, 1n, can carry two electrons, while the next shell, 2n, can carry eight, and the third shell, 3n, can carry up to eighteen.
The third shell carries 18 electrons; 2 in a 3s orbital; 6 in three 3p orbitals; and 10 in five 3d orbitals. The fourth shell carries 32 electrons; 2 in a 4s orbital; 6 in three 4p orbitals; 10 in five 4d orbitals; and 14 in seven 4f orbitals.
The element would be phosphorus. Its electron configuration is [tex]1s^2 2s^2 2p^6 3s^2 3p^3[/tex]
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Why do.we need inactive ingredients?
Answer:
Inactive ingredients are components of a drug product that do not increase or affect the therapeutic action of the active ingredient, which is usually the active drug. Inactive ingredients are added during the manufacturing process of pharmaceutical products such as tablets, capsules, suppositories, and injections
which of the following is a scientific question about the cuttlefish?
Answer:
How does the cuddle fish change its colors?
Please tell me if I'm wrong.
Increasing temperature can
Is iodine a atom,a molecule,an ion or a formule unit?
Answer:
It's an atom
Explanation:
It can't be a molecule since it's only one element, the ion would've been Iodide (I-), and it's not a formula
