Ernest Rutherford's gold foil experiment discovered that atoms have a dense central nucleus with positive charge, surrounded by low-mass electrons in mostly empty space, leading to the nuclear model of the atom.
Ernest Rutherford's gold foil experiment demonstrated that atoms have a small, dense nucleus where most of the mass and the positive charge is concentrated. This experiment, which bombarded a thin sheet of gold with alpha particles, showed that while most of these alpha particles passed through the gold foil, a small fraction were deflected, and an even smaller number bounced back. This was a result of the alpha particles colliding with something dense and positively charged, leading Rutherford to propose the nuclear model of the atom. This model shows that the majority of the atom is empty space and that the negatively charged electrons orbit this central nucleus.
Rutherford's findings refuted the then-prevailing Thomson model, also known as the plum pudding model, which imagined electrons embedded within a positively charged 'paste' that filled the entire volume of the atom. Instead, his results indicated that the nucleus of the atom is tiny in volume but contains the bulk of the atom's mass and is surrounded by low-mass electrons moving through largely empty space.
phosphorus has an atomic mass of 31 and an atomic number of 15 ,so the number of nuetrons must be ?
A biochemist performs an experiment to study the behavior of water molecules near proteins. He concludes that water molecules occur in groups of five in the presence of proteins. Skepticism is important in this scenario because it would help him to
Skepticism is important to the biochemist to critically evaluate and verify the conclusion about the behavior of water molecules near proteins.
Explanation:Skepticism is important in this scenario because it would help the biochemist to critically evaluate and verify the conclusion that water molecules occur in groups of five in the presence of proteins. By maintaining a skeptical mindset, the biochemist can consider alternative explanations, conduct further experiments, and review existing research to ensure the validity and accuracy of the conclusion. Skepticism plays a crucial role in scientific inquiry and helps to ensure that scientific findings are reliable and trustworthy.
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increase Crop Production food Engineers combine two plants so that each plant strength compensates for the others weakness what is this technique called
Answer: Cross breeding
Explanation: Cross breeding can be defined as the method by which two plants can be crossed to produce the desired character and compensate the useless characters shown by the plants individually.
Suppose a plant produces pink flower but small slower and another plant produces white flower but big flower.
If we want big pink colored flower then, these two plants can be crossed among each other so to produce the desired characters and hide the useful characters.
What is the difference between an ionic bond and an covalent bond?
A) An ionic bond is a bond between charged atoms, while covalent is a bond between neutral atoms.
B) An covalent bond is a bond between charged atoms, while an ionic bond is a bond between neutral atoms.
C) A ionic bond shares electrons, while a covalent bond is an attraction between opposite charges.
D) A ionic bond is a bond between charging atoms, while a covalent bond is bond between opposite charges.
Answer:
a
Explanation:
1. Gases are made up of molecules which are relatively far apart.
2. The molecules are in motion at high speeds.
3. The molecular collisions are perfectly elastic.
4. Increase in temperature increases the kinetic energy of the molecules.
Which of the above assumptions accounts for the compressibility of gases as compared to liquids and solids?
A) 1
B) 2
C) 3
D) 4
E) 2 and 3
F) 3 and 4
The assumption that accounts for the compressibility of gases is that gases consist of molecules which are relatively far apart, meaning the correct answer is A) 1.
In regards to the compressibility of gases, the relevant kinetic molecular theory assumption is that gases consist of molecules which are relatively far apart. This is captured in assumption 1 provided in the student's question. When the particles are far apart, there is a considerable amount of empty space between them compared to liquids and solids. This space allows gases to be compressed, as-the molecules can be brought closer together without significant repulsive forces coming into play due to the fact that there are no significant intermolecular forces acting over these large distances. Therefore, the correct answer to the question - which assumption accounts for the compressibility of gases as compared to liquids and solids - is A) 1.
Find the equilibrium concentrations of A, B, and C for a=1, b=1, and c=2. Assume that the initial concentrations of A and B are each 1.0 M and that no product is present at the beginning of the reaction.
Consider the following reaction and associated equilibrium constant:
aA(g)+bB(g)⇌cC(g), Kc = 4.0
Final answer:
To find equilibrium concentrations for the given chemical reaction with Kc=4.0, we use an ICE table to set up the initial concentrations, calculate the change, and determine the equilibrium concentrations for each species. We solve for 'x' the amount of reactants that change to form the products, and then back-calculate the concentrations of A, B, and C at equilibrium.
Explanation:
The student's question requires understanding how to calculate equilibrium concentrations for a chemical reaction with a given equilibrium constant (Kc). The reaction given is aA(g) + bB(g) ⇌ cC(g), with Kc = 4.0. To find the equilibrium concentrations of A, B, and C, we can set up an ICE (Initial, Change, Equilibrium) table, with initial concentrations of A and B at 1.0 M and C at 0 M. If x is the amount of A and B that react to reach equilibrium, then the equilibrium concentrations would be [A] = 1 - ax, [B] = 1 - bx, and [C] = cx. We then plug these into the equilibrium expression Kc = [C]c / ([A]a[B]b).
For the given reaction where a = 1, b = 1, and c = 2, and given Kc, we substitute 1 - x for [A] and [B], and 2x for [C], since no C is initially present. We would then solve for x and back-calculate [A], [B], and [C]. However, to give a definitive answer, we would need the actual values for a, b, and c applied to this specific reaction, not the placeholders.
what happens when air becomes warme and drier as it moves down the Leeward side
Which compound represents the compound aluminum iodide?
Answer: The compound represents aluminium iodide is AlI3.
Explanation:
The algebraic sum of the oxidation numbers of atoms that combined in a neutral and stable molecule must be zero.It is known that the oxidation state of Al is (3+) and of iodide ion is (-1) .The (Al) ion must bonded by 3 atoms of (I) ion, then it will be AlI3.Also, a monoiodide can find a role in the Al-I system, but the compound AlI is unstable at room temperature and converted to the triiodide form as shown in the following equation: 3 AlI → AlI 3 + 2 AlWhich equation shows how to calculate how many grams (g) of KCL would be produced from 4 mol KOH the balanced reaction is mgcl2 + 2koh -> mg(oh)2 + 2kcl?
Is Co a chemical compound
The radius of which of the following orbit is same as that of the first Bohr's orbit of hydrogen atom?
A) He+ (n=2)
B) Li2+ (n=2)
C) Li2+ (n=3)
D) Be3+ (n=2)
where n=orbit ...?
What role do valence electrons play in the formation of compounds from elements?
Final answer:
Valence electrons are pivotal in chemical bonding, participating in either sharing (covalent bonding) or transferring (ionic bonding) to achieve stable electronic configurations aimed at fulfilling the octet rule. Electronegativity influences the nature of these bonds, and the valence bond theory explains the formation of stable compounds through energy considerations.
Explanation:
Valence electrons play a crucial role in the formation of compounds from elements. These electrons are located in the atom's outermost shell and are the primary participants in chemical bonding. Elements combine to form compounds by either sharing valence electrons (covalent bonding) or transferring them (ionic bonding) to achieve stable electronic configurations, often aiming for the octet rule, which is a full set of eight valence electrons that provides stability, reminiscent of the noble gases.
Electronegativity significantly influences how these electrons are shared or transferred. Atoms with higher electronegativity tend to attract valence electrons more strongly, leading to polar covalent or ionic bonds depending on the difference in electronegativity between the bonding atoms.
When 1 mole of tin IV oxide is heated with 2 moles of hydrogen gas, 1 mole of tin metal and 2 moles of water vapor are generated. SnO2 + 2H2 → Sn + 2H2O How many moles of tin metal will be produced when 0.74 moles of tin IV oxide is heated?
Answer : The moles of tin metal produced will be, 0.74 mole
Explanation : Given,
Moles of [tex]SnO_2[/tex] = 0.74 mole
The given balanced chemical reaction is,
[tex]SnO_2+2H_2\rightarrow Sn+2H_2O[/tex]
From the balanced chemical reaction, we conclude that
As, 1 mole of [tex]SnO_2[/tex] react to give 1 mole of Sn
So, 0.74 mole of [tex]SnO_2[/tex] react to give 0.74 mole of Sn
Therefore, the moles of tin metal produced will be, 0.74 mole
Which temperature is coldest??
The temperature 0 degree Celsius is the coldest temperature , Option B is the correct answer.
The complete Question is attached with the answer in form of image
What is Temperature ?The degree of heat a body has measured by the thermometer is called Temperature.
It is asked in the question to determine , which temperature is coldest among the option given
The temperature 0 degree Celsius is the coldest temperature among the options given as it is the lowest
Therefore Option B is the correct answer.
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If the symbol X represents a central atom, Y represents outer atoms, and Z represents lone pairs on the central atom, the structure Y--X(with 2 lone pairs)--Y can be abbreviated as XY2Z2
Classify these structures by the hybridization of the central atom in either..
classify the abbreviations into each hybridization category
HYBRIDIZATIONS:
sp
sp2
sp3
sp3d
sp3d2
ABREVIATIONS:
XY2
XY3
XY4
XY5
XY6
XY2Z3
XY2Z
XY3Z2
XY4Z
XY4Z2
XY3Z
XY5Z
XY2Z2
Draw a complete Lewis structure for the conjugate acid of nitromethane that shows all bonds, unshared electron pairs, and minimized formal charges, where appropriate.
Answer:
Lewis structures are shown below
Explanation:
In Lewis structure of nitromethane, a negative charge is present on oxygen atom in nitro group.Hence this oxygen atom acts as a basic center preferably.Therefore conjugate acid of nitromethane should be drawn by adding a hydrogen atom with this oxygen atom.Lewis structure of nitromethane as well as it's conjugate acid has been shown below including all the lone pairs and formal chargesThe Maunder Minimum would include which of the following years?
Which equilibrium describes a reversible reaction a short time after starting the reaction with reactants only?
- N2(g) + 3H2(g) 2NH3(g)
-N2(g) + 3H2(g) 2NH3(g)
-N2(g) + 3H2(g) 2NH3(g)
-N2(g) + 3H2(g) 2NH3(g)
-N2(g) + 3H2(g) 2NH3(g)
The right answer is N2(g) + 3H2(g) => 2NH3(g).
Ammonia (NH3) is produced by the synthesis of nitrogen (N2) and hydrogen (H2):
N2 + 3 H2 → 2 NH3
During the first half of the 20th century, the NH3-green was produced without CO2 emission at
from hydroelectricity, water, and atmospheric air.
H2 came from the electrolysis of water, the N2 of atmospheric air.
what is mole concept?
When is a secondary source more helpful than a primary source?
A: When you are an expert in the field being studied in the experiment
B: When you do not need many details about the experiment
C: When you want to know the exact data values
D: When you do not need to know the conclusion of the experiment
Answer:
B: When you do not need many details about the experiment
Explanation:
Primary Sources are the first-hand accounts of the topic.
Secondary sources are the scholarly books or articles.
The secondary source interprets and also analyzes the primary sources.
Thus, secondary data can be used as a precursor for publishing new primary data.
Thus, Option B: When you do not need many details about the experiment is correct.
Select all that apply.
Which of the following are interactions between particles in a liquid?
ionic bonds
covalent bonds
van der Waals forces
metallic bonds
hydrogen bonds
Answer is: van der Waals forces and hydrogen bonds.
Intermolecular forces are the forces between molecules or particles.
There are several types of intermolecular forces: hydrogen bonding, ion-induced dipole forces, ion-dipole forces andvan der Waals forces.
Hydrogen bond is an electrostatic attraction between two polar groups that occurs when a hydrogen atom (H), covalently bound to a highly electronegative atom such as flourine (F), oxygen (O) and nitrogen (N) atoms.
Covalent bonds, ionic bonds and metallic bonds are intramolecular interactions, bonds between atoms in molecule.
What relationship exists between the mass number of an element and the isotopes of that element?
which pair of elements is most likely to form an ionic bond?
A:hydrogen and helium
B:lithium and potassium
C:potassium and iodine
D:iron and zinc
how many significant gigures are in each mesasurments 303,000mm
Select the ion.
a) NO2
b)H2SO4
c) Al+3 ...?
i would go with C. Al+3
In each of the following pairs of compounds, which compound is likely to be more soluble in CCl4?
a) Br2 or NaBr
b) CH3OH or C6H11OH
c) CS2 or KOH
d) I2 or CaF2
The principle 'like dissolves like' is used to determine the solubility of compounds in CCl₄. These are more likely to dissolve: Br₂ over NaBr, C₆H₁₁OH over CH₃OH, CS₂ over KOH, and I₂ over CaF₂.
Explanation:The solubility of compounds in CCl₄ can be calculated using the principle 'like dissolves like', which means that substances with similar types of molecular interactions dissolve in each other. Therefore, compounds with similar polarity will dissolve in each other.
a) Br₂ vs NaBr: Br₂, being nonpolar like CCl₄, is expected to be more soluble. NaBr is an ionic compound, and hence it won't dissolve well.b) CH₃OH vs C₆H₁₁OH: Both are alcohols but CH₃OH contains polarity due to the presence of O-H bonds whereas C6H11OH is less polar. Therefore, C6H11OH would be more soluble in CCl₄.c) CS₂ vs KOH: CS₂ is a nonpolar compound like CCl₄, hence it is expected to be more soluble. KOH is ionic and wouldn't dissolve well.d) I₂ vs CaF₂: I₂ is nonpolar and would therefore be more soluble in CCl₄. CaF₂ is ionic and wouldn't dissolve well.Learn more about Solubility here:https://brainly.com/question/28170449
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Final answer:
The more soluble compounds in carbon tetrachloride (CCl₄) are those that are non-polar: Br₂, C₆H₁₁OH, CS₂, and I₂, because CCl₄ is a non-polar solvent and 'like dissolves like'.
Explanation:
The question asks which compound in each pair is likely to be more soluble in carbon tetrachloride (CCl₄). Solubility often depends on the similarity principle 'like dissolves like', meaning that polar solvents dissolve polar substances, and non-polar solvents dissolve non-polar substances.
a) Br₂ or NaBr: Br₂ (bromine) is a non-polar molecule, while NaBr (sodium bromide) is an ionic compound. Br₂ will be more soluble in CCl₄ since both are non-polar.
b) CH₃OH or C₆H₁₁OH: C₆H₁₁OH (cyclohexanol) is less polar and has a longer non-polar hydrocarbon chain compared to CH₃OH (methanol). Thus, C₆H₁₁OH will be more soluble in CCl₄.
c) CS₂ or KOH: CS₂ (carbon disulfide) is a non-polar molecule, while KOH (potassium hydroxide) is an ionic and polar compound. CS₂ will be more soluble in CCl4.
d) I2 or CaF₂: I₂ (iodine) is a non-polar molecule, while CaF₂ (calcium fluoride) is an ionic compound. I2 will be more soluble in CCl₄.
Chemical changes ________ involve the breaking and making of chemical bonds.
A) Always
B) Never
C) Sometimes
Fill in the blank
Answer:
A: Always.
Explanation:
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There are 9 cherry cokes, 3 diet cokes, and 4 coke zeros in a cooler. Selecting a drink and getting a cherry coke, then a coke zero, without replacement makes this probability independent or dependent?
If 255 g of water has 10.0 g of nacl dissolved into initially, how much nacl must be added in order to raise the mass percent of nacl by 10%
Answer: 30.8 g
Explanation:
what trend in atomic radius do you see as you go down a group on the periodic table
The trend in atomic radius as you go down a group on the periodic table is an increase. This is because each successive element adds a new electron shell, meaning the outer electrons are further from the nucleus, and more shielded from the nuclear charge by inner shell electrons.
Explanation:In the Periodic Table, the atomic radius trend seen as you move down a group (a vertical column) is that the atomic radius increases. This trend is due to the increase in the principal quantum number (n level) causing an increase in the size of the electron cloud around the nucleus, making the atomic radius larger. For example, within the group of alkali metals (Group 1), lithium (Li) at the top has a smaller atomic radius than sodium (Na) below it, which is smaller than potassium (K) beneath it, and so forth.
One reason the atomic radius increases as one goes down a group is that with each successive element, a new electron shell is being added. This means that the outer electrons are located further from the nucleus and more shielded from the nuclear charge by inner shell electrons. The effective nuclear charge experienced by the outermost electrons is therefore less, which means the electrons can reside further from the nucleus, leading to an increase in atomic radius for elements down a group.
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