Answer:
Mass number
Nucleus
Explanation:
The combined number of protons and neutrons is the mass number in atomic notation.
The atomic number is just the number of protons alone.
The nucleus holds both neutrons and protons.
Electrons circle around the nucleus.
Answer: atomic mass I did it
Explanation:
The intake stroke of a positive displacement compressor is most similar to that of a
A. thermostatic expansion valve.
B. auxillary electric water pump.
C. one-stroke variable displacement compressor.
D. two-stroke cylinder engine.
Answer:
D. two-stroke cylinder engine.
Explanation:
Two-stroke cylinder engine: In chemistry, the term "two-stroke cylinder engine" is described as one of the types of "internal combustion engine" that tends to complete a single "power cycle" possessing two different strokes of the "piston" during a particular "crankshaft revolution".
It generally consists of two different strokes that are being often known as power or exhaust and suction stroke.
In the question above, the given statement signifies the "two-stroke cylinder engine".
What’s the capital city of Turkey?
Answer:
Ankara is the capital of Turkey! Hope this helped you out! :)
Explanation:
The capital of Turkey is Ankara
hopefully this helped :3
Suppose a 22.092 g sample of a 1:1 mixture of acetylferrocene and ferrocene was separated by column chromatography, and the recovered fractions weighed 9.017 g (acetylferrocene) and 8.075 g (ferrocene), what was the percent recovery of acetylferrocene?
Answer:
81.6%
Explanation:
mass of acetylferrocene and ferrocene mixture = 22.092 g
mass ratio acetylferrocene and ferrocene mixture = 1 : 1
The sum of the ratios = 2, therefore the mass of each compound will be half the mass of the mixture
mass of each compound in the sample mixture = 1/2 * 22.09 2= 11.046 g
mass of recovered acetylferrocene = 9.017 g
percentage recovery = mass recovered/mass in sample * 100%
percentage recovery of acetylferrocene = (9.017 g / 11.046 g) * 100%
percentage recovery of acetylferrocene = 81.6%
The graph compares the kinetic energies of the molecules in four gas samples. Each graph shows a normal distribution, so the average is the center. Which sample is likely to have the lowest temperature? (1 point) A B C D
Answer:
d
Explanation:
i got it right
Gas A is likely to have the lowest temperature. Hence, option A is correct.
What are molecules?The smallest particle of a substance has all of the physical and chemical properties of that substance. Molecules are made up of one or more atoms.
In a gas, the kinetic energy is directly proportional to the temperature under constant pressure and volume.
As you can see in the problem, the average of A has low kinetic energy. But the average is increasing between B, C and D.
As gas A has the lowest average kinetic energy:
Gas A is likely to have the lowest temperature
Hence, option A is correct.
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In heating and melting curves, what is the name of the heat associated with the solid-liquid phase? A. Heat of formation B. Heat of fusion C. Heat of sublimation D. Heat of vaporization
Answer:
C I believe not quite sure tho
In heating and melting curves, the name of the heat associated with the solid-liquid phase is Heat of fusion.
What is the Heat of fusion ?
The standard fusion enthalpy is the amount of thermal energy required for a single mole of a substance to change states from a solid to a liquid or vice versa is known as the heat of fusion or specific melting heat. The melting point is the temperature at which it takes place, and it is also known as the latent heat of fusion or the enthalpy change of fusion.The temperature of a liquid or solid goes down when thermal energy is taken away. The temperature rises when heat and energy are added. However, additional energy—the heat of fusion—is required at the melting point—the transition point between solid and liquid. The molecules of a substance need to become more organized in order to change from liquid to solid. They require the withdrawal of additional heat in order to maintain their solid state. In the opposite direction, additional heat is required to induce the disorder from the solid crystal to the liquid.The temperature of water as it freezes can be measured to observe the heat of fusion. When you place a closed container of room temperature water in a very cold environment, say 20 °C, the temperature will gradually fall until it is just below the freezing point. After that, the temperature rises and stays the same as the water crystallizes. The temperature will again fall steadily after it has completely frozen.The heat of fusion causes the temperature to stop falling at (or just below) the freezing point. Before the temperature can continue to fall, the energy from the heat of fusion must be removed—the liquid must transform into a solid.
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Select the correct answer.
Which of these conditions would most likely cause a decrease in the population of any species?
ОА.
increased competition for resources
improved access to mates
OC.
elimination of predators
OD
decrease in pathogens
Answer(A increased competition for resources
Hope you get it right have a nice day
Answer:
A. increased competition for resources
Explanation:
What do neurons and protons have in common?
Answer:
Protons and neutrons have almost the same mass and are both located in the nucleus of the atom
Answer:
Protons and neutrons have almost the same mass and are both located in the nucleus of the atom. Protons are charged particles. Neutrons are neutral particles. ... The positive charge of the protons in the nucleus is balanced by the negative charge of the electrons.
How to know number of proton/electron from ionisation energy?
also how to know ionisation energy from number of electron?
How to know group of element? (like Iodine - group 17)
Answer:
Ionization energy decreases from top to bottom in groups as the size of the atom becomes larger. For example, the first ionization energy of hydrogen is 1310 kJ mol⁻¹. The first ionization energy of lithium is 519 kJ mol⁻¹. Because lithium is a bigger atom and has more protons than hydrogen, its ionization energy is lower. So, in groups, the lower the ionization energy, the larger the atom and the more protons/electrons it has.
Ionization energy also increases from left to right across a period. The more protons in the nucleus, the greater the attraction between the nucleus and the electrons, which makes it more difficult to remove electrons. Helium has an ionization energy of 2370 kJ mol⁻¹ while hydrogen has an ionization energy of 1310 kJ mol⁻¹ because helium's nucleus has 2 protons attracting electrons instead of 1 like hydrogen. So for periods, the higher the ionization energy, the smaller the atom and the more protons/electrons it has.
Ionization energy is the energy required to remove an electron from its orbital around an atom. It increases across a period because the number of protons in the nucleus increases. This creates a stronger attraction between the nucleus and electrons, causing the electrons to be held tighter by the higher nuclear charge. Because the electrons are more difficult to remove, more energy is required which causes the ionization energy to be higher. So for periods, the more electrons the atom has, the higher the ionization energy. Ionization energy decreases down a group because the first electron removed is farther from the nucleus as the number of protons increases. Being farther away from the nucleus makes it easier for the electron to be pulled off as it is more loosely bounded, so less energy is required to remove the electron which causes the ionization energy to be lower. So for groups, the more electrons the atom has, the lower the ionization energy.
Groups are vertical columns going down on the periodic table. If you look at a periodic table, across the top, you will see the numbers 1-18. Those numbers signify the 18 groups of the periodic table. Iodine is a halogen so it is under Group 17 to the far right of the periodic table.
I attached two periodic tables for reference to everything that I've said as I've written a lot. Hope that helps.
NaHCO3+HCI--->NaCI+H2O+CO2
Percent yield:93.4%
how would the percent yield be affected if some sodium hydrogen carbonate is left unreacted? explain
Answer:
Explanation:
percent yield is ratio of actual yield or experimental yield divided by theoretical yield multiplied by 100 .
percent yield of 93.4 % means , the actual yield is 93.4 % what was expected from the reaction on the basis of given chemical reaction .
If in the experimental process , some sodium hydrogen carbonate is left unreacted due to absence of reactant HCl which is also required to obtain product , the percent yield will be increased if the required HCl is also provided .
Hence the percent yield will be increased if required HCl is made available .
name all the period 2 elements in mendeleevs periodic table
Answer:
beryllium, magnesium, calcium, strontium, barium, radium
Explanation:
glad to help
which of the following would be an appropriate situation for you to use the eye wash station
Answer:
if your eyes are exposed to a hazardous chemical you should use the eye wash station. The first few seconds after exposure to a hazardous chemical are critical.
Based on the kinetic molecular theory, which of the following statements is correct about the particles in a sample of gas at a constant temperature and
volume?
They have negligible kinetic energy
They attract each other with strong forces.
There is a lot of empty space between them.
Their net kinetic energy decreases due to collisions.
Answer:
There is a lot of empty space between them.
Explanation:
The kinetic molecular theory postulates that a substance is made up of tiny particles called molecules. The molecules of a gas are in constant random motion and collide elastically with each other. They also collide with the walls of the container.
The magnitude of intermolecular forces of attraction between gas molecules is very small. Hence gas molecules are largely apart with a lot of empty space between gas molecules.
Answer:C, There is a lot of empty space between them.
Explanation:
A molecule of chlorine has atoms of the same element, and a molecule of carbon dioxide has different kinds of atoms. Based on this information, chlorine is and carbon dioxide is .
Answer:
chlorine is element and carbon dioxide is compound
Answer:
The correct answer would be that Chlorine is an Element and Dioxide is an Compound.
Assertion: When a strong acid is added to a buffer system consisting of a weak acid (HA) and its conjugate base (A-), the concentration of the conjugate base increases. Reason: A stoichiometric amount of the weak acid is converted to its conjugate base. Group of answer choices
Answer:
Both the assertion and reason are false
Explanation:
A buffer is a solution that resists changes in acidity and alkalinity. When a solution is buffered, it pH can only vary within a small range. A buffer is made up of a weak acid/base and its salt.
When a strong acid is added to a buffer solution, the conjugate base will react with the H+ from the strong acid to form the undissociated weak acid HA as follows; H+(aq) + A- (aq)→ HA(aq). Hence, H+ concentration decreases owing to its reaction with the A- thus the pH changes only slightly.
At the time when the strong acid should be added so here Both the assertion and reason are false
What is buffer?It is a solution that resists changes with respect to the acidity and alkalinity. When a solution should be buffered, it pH can only change within a small range. At the time when a strong acid should be added to a buffer solution, the conjugate base should be react with the H+ from the strong acid to form the undissociated weak acid.
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Triangle DEF is congruent to TriangleD'EF' by the SSS theorem. Which single rigid transformation is required to map TriangleDEF onto TriangleD'EF'? dilation reflection rotation translation
Answer:
B. reflection
Explanation:
Rigid transformations are methods involved in changing the dimensions or orientation of a given figure. The methods are; dilation, rotation, translation and reflection.
Reflection is the process in which a given figure is turned or flipped with respect to a point or line of reference.
In the given question,
ΔDEF ≅ ΔD'EF' (Side-Side-Side congruence property)
This implies that ΔDEF was reflected about point E to produce ΔD'EF'. Thus the required rigid transformation is reflection.
Answer:
Is C - Rotation
Explanation:
I have right on my test
hello:)!! for the preparation of salts , I don’t really understand the part where acids react with insoluble bases. do I just memorise it? :) thanks!
Answer:
I think if u will clear your topic it would be more helpful.
But if u r unable to do it, then u can just memorise it.
See, i will try to help u.
Salts are formed when acids react with bases.
and this reaction is called neutralisation reaction.
e.g. HCl+NaOH=NaCl+H2O.
It is very easy.
Other examples:
H2SO4+Mg(OH)2=MgSO4+2H2O.
There may be some other reactant with acid like u have mentioned above.
hope it helps u....
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The radioactive isotope used for carbon dating is
1. Carbon 12
2. Carbon 13
3. Carbon 15
4. Carbon 14
Carbon 14 would be your answer, however if it's more than one answer it would also be Carbon 12, so yeah. Your best bet would be Carbon 14.
answer the question briefly: How can atom collapse and why are atoms stable?
The nuclei of atoms become unstable when the repelling forces of the protons cannot be balanced by the number of neutrons in the nucleus. It then re-arranges itself randomly to a more stable configuration by emitting any of a series of particles. During radioactive decay, an atom does not collapse.
Since an atom is mostly empty space - that is it’s nucleus is relatively distant from the electron shells so, in the presence of extreme forces such as gravity inthe collapse of a large star, the inward pressures on the atom overcome the natural balance of the atomic structure and the ‘empty space’ disappears as nuclei are mashed together by the intense pressures and a neutron star is formed. Under even more external pressure, even the neutron star can collapse to form a black hole.
Adding a base to a solution would...?
Answer:
it would decrease [h+]
Explanation:
This is due to neutralization If a base is added to an acidic solution, the solution becomes less acidic and its position changes to the middle of the pH scale.
hope this helps
Answer:
Raise the pH
decrease [H+]
Explanation:
=> Adding base would raise the pH (Bases have more pH and Acids have less pH)
=> Adding base would decrease the concentration of [H+] ions as it contains hydroxyl ions which neutralized with H+ ions so as a result the concentration of [H+] ions decreases.
Which of the following will only affect the reaction rate of gases?
A. Concentration
B. Catalyst
C. Pressure
D. Surface area
Answer:
D. Pressure
Explanation:
The rate of a reaction is defined as the speed at which the reactants are converted into products. Factors influencing the rate of a reaction are concentration, catalyst, temperature, surface area, and pressure, etc.
In case of the reaction rate of gases, pressure will only have its affect as pressure do not have any influence on solid and liquid.
While concentration, surface area and catalyst influence all reaction rates including solid, liquids and gases.
Hence, the correct option is (d) pressure.
What is the freezing point of a solution of 1.43 g mgcl2 in 100 g of water? Kf for water is 1.86°c/m for water.
Answer:
Change in T = i x m x kf. Where i is the number of particles the compound dissociates, m is the molality, and kf is the constant specific to water. MM of MgCl2 = 95.21 g/mol
MgCl2 will form three atoms....i = 3......1Mg + 2Cl
kf = 1.86
moles of MgCl2 = 1.43g/95.21 = 0.015
m = moles solute/ kg solvent = 0.015/.1kg = .15m
Change in T = (3)(.15)(1.86) = .838
This is the depression of the freezing point of water, it is negative because the water's new freezing point is its normal freezing point minus the change in T.
0 - .838 = -.838
Explanation:
------------neutral particles in an atom
Answer:
neutrons :
Explanation:
Protons are positively charged, while electrons are negatively charged. Neutrons are electrically neutral, as the name suggests. The electric charge, noted Q , is a physical quantity.
A buffer solution contains 0.500 mole per liter each of acetic acid and sodium acetate. Determine the pH of the solution. The Ka of the acetic acid is 1.74 x 10-5. (Need an in-depth explanation with formulas please)
Answer:
The pH of the solution is 4.76
Explanation:
The concentration of the acetic acid and sodium acetate are 0.500 mole per liter each
The Kₐ of the acetic acid is 1.74 × 10⁻⁵
The concentration of the acetic acid CH₃COOH = 0.500 mole per liter = 0.5 M
The concentration of the sodium acetate (conjugate base) = NaCH₃COO = 0.500 mole per liter = 0.5 M
The dissociation constant, Kₐ, is given by the relation;
[tex]K_a = \dfrac{[H_3O^+][CH_3COO^-]}{[CH_3COOH]}[/tex]
Therefore, we have;
Kₐ × [CH₃COOH]/[CH₃COO⁻] = [H₃O⁺]
1.74×10⁻⁵×0.5/0.5 = 1.74 × 10⁻⁵
Therefore, [H₃O⁺] = 1.74 × 10⁻⁵
pH = -㏒₁₀(1.74×10⁻⁵) = 4.76
The pH of the solution = 4.76.
write chemical equation for the following decomposition reactions. Aluminum oxide(s) decomposes when electricity is passed through it.
Answer:
2Al2O3 (l) ---> 4Al (l) + 3O2 (g)
Explanation:
The reaction is the electrolysis of aluminium oxide. It decomposes aluminium oxide (Al2O3) into aluminium metal (Al) and Oxygen (O2). In this process, aluminium oxide is molten (liquid state) so that ions can move to complete the electricity circuit.
Al2O3 (l) ---> Al (l) + O2 (g)
Balance the equation:
2Al2O3 (l) ---> 4Al (l) + 3O2 (g)
Un compuesto ZO2 tiene masa molar igual a 64. La masa atómica de Z debe ser: A . 6. C. 12. E. 32. B. 10. D. 24.
Answer:
32. Opcion E
Explanation:
ZO₂ podemos entenderlo como dióxido de Z
1 mol de ZO₂ contiene 1 mol de Z y 2 moles de O₂ por lo que si la masa molar es de 64 g/mol, podemos plantear lo siguiente
Masa de Z + 2 masa de O = 64 g/mol
Sabemos que la masa del oxígeno es 16 g/mol
x + 2. 16 g/mol = 64 g/mol
x = 64 - 32 → 32 g/mol
La masa atómica coincide con la masa molar, por lo tanto la masa atomica de Z es 32.
Considerando la definición de masa molar, la respuesta correcta es la opción E: La masa atómica de Z debe ser 32.
La masa molar es la masa de un mol de una sustancia, la cual puede ser un elemento o un compuesto, esto es, es la relación entre la cantidad de sustancia y su masa.
En otras palabras, la masa molar es la cantidad de masa que una sustancia contiene en un mol.
En la tabla periódica, se puede encontrar la masa molar de los elementos, también llamada masa atómica o peso atómico.
Para calcular la masa molar de un compuesto, también llamado masa o peso molecular, se debe sumar la masa molar de los elementos del compuesto multiplicado por su cantidad en el compuesto.
Entonces, en este caso, siendo la masa molar del oxígeno (O) 16, y la masa molar del compuesto ZO₂ 64, y denominando x a la masa molar de Z, entonces la masa molar del compuesto puede expresarse como:
x + 2×16= 64
Resolviendo:
x + 32= 64
x=64 -32
x=32
Finalmente, la respuesta correcta es la opción E: La masa atómica de Z debe ser 32.
Aprenda más:
https://brainly.com/question/23183573?referrer=searchResultsIn the reaction MgCl2 + 2KOH → Mg(OH)2 + 2KCI, how many grams of KOH
react with 1 mole of MgCl2?
A. 95 g
B. 56 g
C. (1/2)(56 g)
O D. (2)(56 g)
Answer:
The correct option is;
D. (2)(56 g)
Explanation:
MgCl₂ + 2KOH → Mg(OH)₂ + 2KCl
From the balanced chemical reaction equation, we have;
One mole of MgCl₂ reacts with two moles of KOH to produce one mole of Mg(OH)₂ and 2 moles of KCl
Therefore, the number of moles of KOH that react with one mole of KCl = 2 moles
The mass, m, of the two moles of KOH = Number of moles of KOH × Molar mass of KOH
The molar mass of KOH = 56.1056 g/mol
∴ The mass, m, of the two moles of KOH = 2 moles × 56.1056 g/mol = 112.2112 grams
The amount in grams of KOH that react with one mole of MgCl₂ = 112.2112 grams ≈ 112 grams = (2)(56 g).
Answer:
the answer is D
Explanation:
good luck
To dissolve in water, aluminum (AI) should form a compound with
oxide (O2-).
sulfide (S2-).
nitrate (NO,-).
phosphate (POP).
Answer:
Explanation:
Nitrate of most of the elements are water soluble . Aluminium nitrate is also one of them . Aluminium nitrate is easily dissolved in water . It forms hydrated salt whose formula is as follows
Al( NO₃ )₃ . 9H₂O
It is a white crystalline salt . It is also soluble in alcohol.
Which of the mechanical waves below has the greatest energy?
Answer:
Blue wave.
Explanation:
The energy of a wave depends on its amplitude. A wave having more amplitude will have greatest energy while a wave having small amplitude will have least energy. The given figure shows four waves that are shown with green, orange, blue and red color. It is very clear from the figure that the amplitude of blue wave is greatest of all the wave.Hence, blue wave will have greatest energy.what particle determines the name of the element?
Answer:
The protons determine the name of an element and also atomic number because its the same as protons.
How did Bohr describe the arrangement of particles within an atom?
A. Protons and electrons form the nucleus, with neutrons
orbiting it.
O B. Neutrons make up the atom's nucleus, with electrons and
protons orbiting it.
c. Protons make up the atom's nucleus, with electrons and
neutrons orbiting it.
O D. Protons and neutrons form the nucleus of the atom, with
electrons orbiting it.
Bohr describe the arrangement of particles within an atom by: O D. Protons and neutrons form the nucleus of the atom, with electrons orbiting it.
Who is Niels Bohr?This hypothesis states that the atom's core is a small, compact, positively charged nucleus. Protons which have a positive charge and neutrons which are neutral are both found in the nucleus.
Specific energy levels or electron shells are where the negatively charged electrons orbit the nucleus. Due to the quantization of these energy levels, only a limited number of discrete energy states are accessible to electrons.
Therefore the correct option is D.
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