Answer:
ones in magnets r close together while others can be spread apart
In Rutherford experiment some alpha particles fired at a gold foil bounced backward as a result of ... A.reflection from the surfaces of gold atoms B.electrostatic repulsion by gold nuclei C.electrostatic repulsion by electronsD.all of the aboveE.none of the above
Answer:
B.electrostatic repulsion by gold nuclei
Explanation:
According to Rutherford's experiment, a thin gold foil was bombarded with alpha particles. Some of the particles passed through the foil undeviated, some were scattered through large angles while some bounced backwards.
It follows that the particles that bounced backwards must have encountered a massive particle of like charge.
The atom is composed of a nucleus which contains positively charged particles. Some of the alpha particles which are positively charged particles bounced back when they encountered the positively charged particles in the nucleus.
Answer: The correct option is B (electrostatic repulsion by gold nuclei).
Explanation:
In the Rutherford's experiment, he used positively charged particles called alpha particles to bombard an atom in order to find out what is inside the atom. Together with two other scientists, Geiger and Marsden, they used a narrow beam of alpha particles emitted from a radioactive source to bombard a thin gold foil. The scattering of the particles from the gold foil was detected by a movable zinc sulphide screen which could be rotated to various positions around the foil.
Each time an alpha particle hit the screen, a visible flash of light or scintillation was produced. This was observed by a microscope attached to the screen. It was then observed that some of the particles followed a straight path through the gold foil while a few where scattered in a backward direction. This was as a result of electrostatic repulsion by gold nuclei which occurs due to the greater part of the mass of the atom was concentrated in a minute nucleus with positive charge.
Identify the product Q in the reaction below
Cl2 +2NaOH ------->NaCL +H2O+Q
Answer:
the product of q in the reaction below is Nacl
Urgent please help
A.Ca
B. CaO
C.CO
How are energy and mass connected during the formation of an
atom?
Answer:
Energy is absorbed, so the mass is increased. Energy is released, so the mass is increased
Describe how a constant volume calorimeter can be used to measure the heat transferred from a burning piece of coal to cool water.
thank you <3
Answer:
A Calorimeter is a device used to measure the amount of heat involved in a chemical or physical process.
Explanation:
Ex- when an exothermic reaction ( accompanied by or requiring absorption of heat)occurs in solution in a calorimeter, the heat produced by the reaction is absorbed by the solution increasing its temperature.
- When an endothermic reaction (Heat evolving reaction) occurs, the heat required is absorbed from the thermal energy of the solution, decreasing its temperature.
A burning piece of coal which is releasing heat due to its combustion and is transferred to water.
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Consider the terms elements, compounds, and mixtures. What do you think each of
these is?
Answer:
Explanation:
Element -
It is the basic unit of matter, which cannot be broken down into substances by any way but can be combined to form new substances.
It is a pure substance.
It classifies into metals, non-metals, metalloids and noble gases.
Example - Hydrogen, Carbon, Oxygen
Compounds -
It is a combination of two or more elements.
It is a pure substance.
Through chemical reactions, they can be broken down into metals.
Example - Water, Carbon dioxide
Mixtures -
It is a combination of two or more elements or compounds or both.
The substances combined in a mixture are in a particular ratio.
Example - Chalk powder, Washing Soda
What is the principle of simple machine?
ASAP
What happens to a glass of pure fruit juice when water is added to it?
A - The number of moles of fruit juice increases.
B - The number of moles of fruit juice decreases.
C - The molarity of the juice increases.
D - The molarity of the juice decreases.
D. The MOLARITY of the juice DECREASES when water is added to it.
MOLARITY refers to the amount of a substance (solute) in a certain volume of solution. It is a measure of the CONCENTRATION OF A SOLUTION. In chemistry, molarity is calculated by dividing the number of moles of a solute by the volume of the solvent i.e.
MOLARITY (mol/L or M) = number of moles (n)/volume of solvent (V)
* The above equation means that the molarity of a solution is inversely proportional to its volume i.e. as molarity increases, volume decreases and vice versa.
According to this question, water is added to a glass of pure fruit juice (dilution). This means that the volume of the juice will increase. As the volume increases via addition of water, the MOLARITY DECREASES.
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If a pile of a deson of Buttons has a height of 2cm 4mm, what is the thickness of one to button.
The thickness of one button will be 2mm
According to this question, a pile of a dozen buttons has a height of 2cm 4mm. A dozen means 12, hence, 12 buttons has a height of 2cm 4mm.* N.B: We convert the height of the 12 buttons to same unit (mm)
Since 1cm = 10mmThen, 2cm = 2 × 10 = 20mm
20mm + 4mm = 24mm
That is, twelve buttons (a dozen) has a thickness of 24mm, one button will therefore, be:24/12 = 2mm thick
Hence, one button is 2mm thick.
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Predict the approximate Ksp of Cuz(AsO4)2 based on the measured potential of Cell 7. Use the equation given in the Background.
a. 1 x 10^-35
b. 4 x 10^14
c. 5 x 10^-17
d. 2 x 10^-21
Answer:
a. 1 x 10^-35
Explanation:
The correct compound given is: [tex]\mathsf{Cu_3(AsO_4)}_2[/tex]
To predict the approximate Ksp value of the given compound, we will need to express the oxidation-reduction half-reaction of the compound and its dissociation, then, we will use the Nernst equation to determine the approximate Ksp value.
To start with the reduction half-reaction:
[tex]\mathsf{Cu_3(AsO_4)_{2}(s) + 6e^- \to 2As O_{4}^{3-}_{(aq)}+3Cu(s) }[/tex]
The oxidation half-reaction is:
[tex]\mathsf{3Cu(s) \to 3CU^{2+}_{(aq)} + 6e^-}[/tex]
The overall cell reaction now is:
[tex]\mathsf{Cu_3(AsO_4)_{2}(s) \to 3Cu^+ (aq) + 2As O_{4}^{3-}_{(aq)} }[/tex]
From the reduction half-reduction, the number of moles of electrons (n) transferred is 6 moles.
By applying the Nernst equation:
[tex]\mathsf{E_{cell} = E^0_{cell} -\dfrac{0.0591V}{n}log [Cu^{2+}]^3[AsO_4^{3-}]^2 }[/tex]
At standard conditions;
The standard cell potential [tex]\mathsf{E^0_{cell} = -0.342 \ V}[/tex]
and [tex]\mathsf{E_{cell} = 0 \ V}[/tex] since it is at equilibrium.
∴
[tex]\mathsf{0 = -0.342 -\dfrac{0.0591V}{6}log [Cu^{2+}]^3[AsO_4^{3-}]^2 } \\ \\ \\ \mathsf{0.342 = -\dfrac{0.0591V}{6}log [Cu^{2+}]^3[AsO_4^{3-}]^2 }[/tex]
[tex]\mathsf{log [Cu^{2+}]^3[AsO_4^{3-}]^2 = \dfrac{-(0.342)*6}{0.0591 }}[/tex]
[tex]\mathsf{log [Cu^{2+}]^3[AsO_4^{3-}]^2 = -34.7}[/tex]
[tex]\mathsf{log [Cu^{2+}]^3[AsO_4^{3-}]^2 \simeq -35}[/tex]
[tex]\mathsf{[Cu^{2+}]^3[AsO_4^{3-}]^2 = 10^{-35}}[/tex]
[tex]\mathbf{K_{sp} = [Cu^{2+}]^3[AsO_4^{3-}]^2 = 1\times 10^{-35}}[/tex]
Nal+ pb(SO4) 2 Pbl4 + Na2SO4 explain how to balance the chemical equation and classify its reaction type
Explanation:
because there are 4 Iodines on the left, we'll put. 4 in front of NaI to balance it. This would result in 4 Na on the left, so we'll put a 2 in front of Sodium Sulfate to balance the right side. Now we have 4 Na and I on both side, as well as 2 Sulfate on both sides. Pb is already balanced. The equation is now complete.
the metric system of units is known as
Answer:
International System of Units (SI)
Explanation:
I hope it helps :)
9. During an experiment the students prepared three mixtures A)Starch in water B) Sodium chloride solution C) Tincture of Iodine. i) Students observed a visible beam of light through mixture A. Why? ii) Tincture of lodTe did not show Tyndall effect. Explain reason. ill) How can you relate particle size to Tyndall effect?
Answer:
See explanation
Explanation:
Tyndall effect refers to the scattering of light in a solution. Tyndall effect occurs when the size of particles in the solution exceeds 1 nm in diameter. Such solutions are actually called false solutions.
In tincture of iodine, the size of particles in solution is less than 1 nm in diameter hence the solution does not exhibit Tyndall effect. Hence, tincture of iodine is a true solution.
Therefore, if the size of particles in solution exceeded 1nm in diameter, Tyndall effect is observed.
Temperature (°C) 5
Heating Curve for Water
160
140
2 120
100
80
60
40
20
0
-20
1 2 3 4 5 6 7
Time (min)
8
9
10
At what temperature does the solid start melting?
0 -20°C
0°C
20°C
80°C
Answer:
Showing results for Temperature (°C) 5 Heating Curve for Water 160 140 2 120 100 80 60 40 20 0 "-20" 1 2 3 4 5 6 7 Time (min) 8 9 10 At what temperature does the solid start melting?
plz solve the question and send the answer
I will give u branist n like u and even follow u back plz help me
Answer:
P¹V¹/T¹=P²V²/T² here
P²= 1.25- atm
V²=?
T²=345K
P¹=0.75-atm
V¹=120
T¹=295K
So V²= (0.75 x120/295)x(345/1.25)
Volume of the gas V²= 84.20- ml
Answer:
Solution given:
at first
volume[tex]V_{1}=120.0ml[/tex]
pressure [tex]P_{1}=0.75atm[/tex]
temperature [tex]T_{1}=22+273=295°K[/tex]
after increasing temperature and pressure
volume[tex]V_{2}=xml[/tex]
pressure [tex]P_{2}=1.25atm[/tex]
temperature [tex]T_{2}=70+273=343°K[/tex]
now
By using Combined gas equation[tex]\frac{P_{1}V_{1}}{T_{1}}=\frac{P_{2}V_{2}}{T_{2}}[/tex]
substituting value
[tex]\frac{0.75*120}{295}=\frac{1.25*x}{343}[/tex]
0.305=5x/1372
Doing criss cross multiplication
5x=0.305*1372
x=418.46/5
x=83.69ml
x=84ml
the volume will be 84ml
What do Van der Waals forces do?
Answer:
they are weak forces that attract neutral molecules to one another
Explanation:
particles in liquid or air vibrate and move constantly thus they collide
(a) How many significant figures should be reported for
the volume of the metal bar shown below? (b) If the
mass of the bar is 104.7 g, how many significant figures
should be reported when its density is calculated using
the calculated volume? [Section 1.5]
The number of significant figures will be four (4)
Which is the best term to use when describing the energy of motion? chemical kinetic potential thermal
Answer:
Kinetic energy
Explanation:
Kinetic energy is the energy associated with an object's motion. It is mass and velocity dependent by a directly proportional relationship.
Potential energy is the energy associated with an object's position.
Thermal energy is the energy associated with heat addition or withdrawal.
Kinetic energy is the energy that a body possesses because of its movement, that is, it is the energy that arises when objects are in motion.
What is kinetic energy?It is that energy that a body or system possesses due to its movement.The amount of work done by all the forces acting on a body with a given mass, depends on the said mass and the speed of the body.Therefore, we can conclude that kinetic energy is the energy produced by its movements that depends on its mass and speed.
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What is the correct equilibrium constant expression for the following reaction?
2NCl3(g) Û N2g) + 3Cl2g
Answer:
K = [N2] [Cl2]³ / [NCl3]²
Explanation:
The equilibrium expression, K, of a reaction:
aA + bB ⇄ cC + dD
Is defined as the ratio between the multiplication of concentrations of products powered to its reaction coefficient and the multiplication of concentrations of reactants powered to its reaction coefficient as follows:
K = [C]^c[D]^d / [A]^a[B]^b
Now, for the reaciton:
2NCl3 ⇄ N2(g) + 3Cl2(g)
K is:
K = [N2] [Cl2]³ / [NCl3]²
15. How many moles of CaCl are in 250. mL of 3.00 M of CaCl solution?
a. 750. mol
b. 1.33 mol
C. 83.3 mol
d. 0.750 mol
e. 3.00 mol
Which redox reaction would most likely occur if silver and zinc metal were
added to a solution that contained silver and zinc ions?
Click for a reduction potential chart
O A. Zn2+ + 2Ag → Zn + 2Agt
B. Zn2+ + 2Agt → Zn + 2Ag
C. Zn + 2Ag → Zn2+ + 2Ag+
D. Zn + Ag? → Zn2+ + 2Ag
Answer:
Zn²⁺ + 2Ag → Zn + 2Ag⁺
Explanation:
According to the reduction potential chart, silver ion (Ag⁺) is a stronger oxidizing agent than zinc (Zn), which is a reducing agent the compared to silver
Therefore, the redox reaction that will occur is that the zinc, Zn, will be oxidized to Zn²⁺ ion, while the silver, Ag²⁺ ion will be reduced to silver deposits Ag, therefore, the zinc will displace the silver in the solution containing silver and zinc ions because zinc is higher than silver in the reactivity series
The reduction potential Zn → Zn²⁺ + 2e⁻ = +0.76
The reduction potential for Ag⁺ + e⁻ → Ag = +0.8
Given that redox reactions are reversible, we get the following likely redux reaction:
Zn(s) + 2Ag⁺(aq) ⇄ 2Ag(s) + Zn²⁺(aq)
Zn²⁺(aq) + 2Ag(s) → Zn(s) + 2Ag⁺(aq) is the reaction most likely to occur.
(True or false) Two or more atoms combine to form a molecule ____
Answer:
false tjytyjiy
Explanation:
cnruujrkyrryyrkkurk
what is meant by reactive elements
Answer; relative elements are most reactive elements and compounds may ignite spontaneously or explosively. They generally burn in water as well as the oxygen in the air
Explanation:
Answer:
Reactive elements are the elements which are ready to gain electrons because they have incompletely filled outermost shell.
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PLZ HELP what is a sign that a chemical change has happened
Answer:
Some signs of a chemical change are a change in color and the formation of bubbles. The five conditions of chemical change: color change, formation of a precipitate, formation of a gas, odor change, temperature change.
What is the shape around each carbon atom in ethylene, H C CH ? The represents a double bond.
linear
trigonal planar
V shaped
tetrahedral
trigonal pyramidal
bent
Answer:
I'm not 100% sure,but I think its trigonal pyramidal
the pH value of 0.1 mol dm-3 of acid U is 1. Which statement is true about acid U?
A) slightly soluble in water
B) reacts only with a weak alkali
C) the degree of ionization in water is high
D) has a low concentration of hydrogen ions
Answer:
the degree of ionization in water is high
Explanation:
The term pH is defined as the negative logarithm of hydrogen ion concentration.
Hence;
pH = -log[H^+]
The pH scale shows the degree of acidity or alkalinity of a solution. A solution of pH 1 is a strong acid. A strong acid dissociates completely in solution.
Hence, acid U has a high degree of ionization in water.
steel cranes can carry heavy steel beams thousands of feet high
Answer:
yes they were made to carry thousands of lb high up
hii pls help me to balance the equation thanksss
Answer:
I hope the link above will be helpful
▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓
[tex]\boxed{\pmb{\green{\sf{3Mg(s) + N_{2}(g)\dashrightarrow Mg_{3}N_{2}(s)}}}}[/tex]
▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓
What is the actual specific heat capacity of the silver in the Calorimetry Lab?
0.234 J/gK
0.133 J/gK
0.035 J/gK
0.023 J/gK
The actual specific heat capacity of the silver in the Calorimetry Lab is given as 0.234 J/gK.
What is specific heat capacity?
Specific heat capacity is the amount of heat required to raise a unit mass of a substance by 1 degree kelvin.
The specific heat capacity of silver or amount of heat required to raise a unit mass of silver metal is 0.234 J/gK.
Thus, the actual specific heat capacity of the silver in the Calorimetry Lab is given as 0.234 J/gK.
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precautive measures taken when using pooter
I guess ensuring that you don't suck the insects or specimen collected by ensuring there is a net in the pooter
