Answer:
Einstein realized that the energy in electrons was caused by the frequency of light and not the intensity of light. This made him realize that he needed to explain the photoelectric effect.
Explanation:
Einstein realized that the photoelectric effect was a system that should be studied and explained in more depth, when he saw how the energy of electrons behaved in the presence of light. He saw that this energy depends entirely on the frequency of light and not on the intensity of light. From this observation, he realized that the photoelectric effect was essential for the production of an electric energy system, through light energy, such as solar energy.
It is important to note that the photoelectric effect refers to the ejection of electrons on a light surface that comes into contact with a light source.
what type of properties change ina physical change? Give an example to support your answer?
pls quick who will give the answer first will get the brainliest
Explanation:
We can observe some physical properties, such as density and color, without changing the physical state of the matter observed. Other physical properties, such as the melting temperature of iron or the freezing temperature of water, can only be observed as matter undergoes. A physical change physical change involves a change in physical properties. Examples of physical properties include melting, transition to a gas, change of strength, change of durability, changes to crystal form, textural change, shape, size, color, volume and density.hope it helps.stay safe healthy and happy.What is Heisnberg's uncertainity principle? Why it make sense only for microscopic particles.
Answer:
The uncertainty principle is one of the most famous (and probably misunderstood) ideas in physics. It tells us that there is a fuzziness in nature, a fundamental limit to what we can know about the behavior of quantum particles and, therefore, the smallest scales of nature.
Which atomic model states that it is impossible to know the exact location of electrons around the nucleus?
Answer:
Bohr Model is the correct answer
Answer:
Electron -Cloud Model
Explanation:
Just took the quiz got 100%
What are the equipments needed to determine the density of a liquid in laboratory ?
Answer:
A hydrometer is a special device used to determine the density of liquids.
Explanation:
I hope this helps you. Have a nice day!
Why do gases act more ideal at
lower pressures?
Answer:
Gases act more ideal at lower pressure beacuse the attractive forces between molecules will decrease or become less significant compared to the empty space between them.
Explanation:
Generally, a gas behaves more like an ideal gas at higher temperature and lower pressure as the potential energy due to intermolecular forces becomes less significant compared with the particles "kinetic energy" and the size of the molecules become less significant compared to the empty space between them.
Attractive forces between molecules, decrease the pressure of a reak gas, slowing the molecules and reducing collisions with the walls.The higher the value of a gas, the greater the attraction between molecules and the more easily the gas will compress.
HOPE IT HELPS MUCHanswered by: John Glenly Pillazo Mahusay
Given 200ul of a 0.5mg/ml stock solution of BSA, how much do you pipet into a test tube so that you are adding 5ug of BSA to the test tube
Answer: [tex]10\mu L[/tex] of volume needs to be pipetted out in the test tube.
Explanation:
We are given:
Mass of BSA to be formed = [tex]5\mu g=0.005mg[/tex] (Conversion factor: [tex]1mg=1000\mu g[/tex]
Volume of stock solution = [tex]200\mu L=0.2mL[/tex] (Conversion factor: [tex]1mL=1000\mu L[/tex]
It is also given that for the mass of BSA is 0.5 g, the volume used up is 1 mL
In order to have, 0.005 g, the volume of stock solution needed will be = [tex]\frac{1mL}{0.5g}\times 0.005g=0.01mL=10\mu L[/tex]
Hence, [tex]10\mu L[/tex] of volume needs to be pipetted out in the test tube.
Compound X has the same molecular formula as butane but has a different boiling point and melting point. What can be concluded about Compound X?
A It is a four-carbon alkene or alkyne.
B It is an optical isomer of butane.
C It is a geometric isomer of butane.
D It is a structural isomer of butane.
need this for gradpoint:)
Answer:
d
Explanation:
Consider the following chemical equilibrium: Now write an equation below that shows how to calculate from for this reaction at an absolute temperature . You can assume is comfortably above room temperature. If you include any common physical constants in your equation be sure you use their standard symbols, found in the ALEKS Calculator.
Answer:
Kp=Kc *(RT)+-3
Explanation:
The relation between Kp and Kc is given below:
Where,
Kp is the pressure equilibrium constant
Kc is the molar equilibrium constant
R is gas constant , R = 0.082057 L atm.mol⁻¹K⁻¹
T is the temperature in Kelvins
Δn = (No. of moles of gaseous products)-(No. of moles of gaseous reactants)
For the first equilibrium reaction:
Δn = (0)-(2+1) = -3
Thus, Kp is:
Kp=Kc *(RT)+-3
We can use bond-line formulas to represent alkenes in much the same way that we use them to represent alkanes. Consider the following alkene: h5ch5e4 How many carbon atoms are sp2−hybridized in this alkene?
Answer:
2
Explanation:
The number of carbon atoms that are sp²-hybridized in this alkene is 2
Because all the single bonded carbon atoms in the alkene are sp²-hybridized
There are three(3) single formed via sp² orbitals and one ( 1 ) PI bond formed via Pure-P-orbital
attached below is the some part of the solution
write Balance chemical reaction for preparation of chlorine with or without application heat
Answer:
2KMnO4(aq) + 16HCl(aq) ------> 2MnCl2(aq) + 2KCl(aq) + 8H2O(l) + 5Cl2(g)
Explanation:
Chlorine is a diatomic halogen gas known for its greenish-yellow colour. It has a pungent smell and is only moderately soluble in water.
It is a very reactive gas and is never found in free state in nature.
Chlorine can be prepared in the laboratory by oxidation of hydrochloric acid using KMnO4 as follows;
2KMnO4(aq) + 16HCl(aq) ------> 2MnCl2(aq) + 2KCl(aq) + 8H2O(l) + 5Cl2(g)
The set up does not need to be heated.
how to separate and purify the Flufenamic acid from the aqueous layer
Answer:
Explanation:
H
1. Arrange the following groups in order of decreasing priority that would allow you to determine E/Z, or R/S. Provide a string of letters (e.g. abcd) as an answer with the highest priority listed first, lowest priority last:
a) -CH3 b) -CH2OH c) -CH2NH2 d) -CH2BR
2. Arrange the following groups in order of decreasing priority that would allow you to determine E/Z, or R/S. Provide a string of letters (e.g. abcd) as an answer with the highest priority listed first, lowest priority last:
a) -F b) -CH2OH c) -CHO d) -CH3
1) The order of decreasing priority would allow determining E/Z or R/S is "dbca".
2) The order of decreasing priority would allow determining E/Z or R/S is "acbd".
What is absolute configuration?Absolute configuration can be described as to the spatial arrangement of atoms within a chiral molecular entity. Absolute configuration in organic molecules, where carbon is bonded to four different substituents.
The absolute configuration has used a set of rules to describe the relative positions around the chiral center atom. The most common labeling method is the descriptors R or S where R and S refer to Rectus and Sinister.
The group with the highest atomic number will get the highest priority and the group with the lowest atomic number substituents will get the lowest priority. Therefore, the order of priority is -CH₂Br > -CH₂OH > -CH₂NH₂ > -CH₃.
Therefore, the order of priority for the second part is -F > -CHO > -CH₂OH > -CH₃.
Learn more about absolute configuration, here:
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6. Which compound contains no ionic character?
Answer:
The compound which doesn't contains ionic character is HC, H-atom and CL- atom shares 1 electron a to form covalent bond....
Calculate the Experimental Molar Volume in L/mol of the Hydrogen gas, H2, if the volume of H2 at STP is 52.8 mL and the mass of Magnesium metal, Mg, used in the experiment is 0.055 g.
Answer:
The Experimental Molar Volume in L/mol of the Hydrogen gas=23.36L/mol
Explanation:
We are given that
Volume of H2 at STP=52.8mL
Mass of magnesium metal ,M(Mg)=0.055g
We have to find the Experimental Molar Volume in L/mol of the Hydrogen gas.
Molar mass of Mg=24.305 g/mol
Number of moles=[tex]\frac{given\;mass}{molar\;mass}[/tex]
Using the formula
Number of moles of Mg=[tex]\frac{0.055}{24.305}[/tex]moles
Number of moles of Mg=0.00226moles
Number of moles of Mg=Number of moles of H2
Number of moles of H2=0.00226moles
Molar volume of Hydrogen gas (H2)=[tex]\frac{volume\;at\;STP}{No\;of\;moles\;H_2}[/tex]
Molar volume of Hydrogen gas (H2)=[tex]\frac{52.8}{0.00226}mL/mol[/tex]
Molar volume of Hydrogen gas (H2)=[tex]\frac{52.8}{0.00226}\times 10^{-3}L/mol[/tex]
[tex]1L=1000mL[/tex]
Molar volume of Hydrogen gas (H2)=23.36L/mol
Hence, the Experimental Molar Volume in L/mol of the Hydrogen gas=23.36L/mol
How many ml of 0.24 M HBr solution are needed to react completely with 10.00 ml of 0.24 M Sr(OH)2 solution
Answer:
10mL
Explanation:
Using the formula as follows:
CaVa = CbVb
Where;
Ca = concentration of acid, HBr (M)
Cb = concentration of base, Sr(OH)2 (M)
Va = volume of acid, HBr (Litres)
Vb = volume of base, Sr(OH)2 (Litres)
According to the information given in this question;
Ca = 0.24M
Cb = 0.24M
Va = ?
Vb = 10.0ml
Using CaVa = CbVb
0.24 × Va = 0.24 × 10
0.24Va = 2.4
Va = 2.4 ÷ 0.24
Va = 10mL
10mL of HBr is needed.
. Gastric juice, the digestive fluid produced in the stomach, contains hydrochloric acid, HCl. Milk of Magnesia, a suspension of solid Mg(OH)2 in an aqueous medium, is sometimes used to neutralize excess stomach acid. Write a complete balanced equation for the neutralization reaction, and identify the conjugate acid-base pairs.
Answer:
Mg(OH)2 + 2HCI = MgCI2 + 2H2O
Explanation:
Please correct me if I am wrong
Draw the Lewis structure for the polyatomic formate anion. Be sure to include all resonance structures that satisfy the octet rule.
Answer:
Lewis structure of polyatomic formate anion.
Explanation:
To draw Lewis structure for any chemical species,
1)Count the total number of valence electrons present in it.
This can be obtained by adding valence electrons of each constituent atom.
2)Arrange those valence electrons in such a way that each atom should attain eight electrons around it to satisfy octet theory.
The structure of formate ion and its Lewis structure are shown below:
HCOO- is the formate ion.
It has total:
1+4+6+6+1 = 18 valence electrons.
Since, hydrogen has one, carbon has four and oxygen has six valence electrons and the charge of the anion is one.
Arrange this 18 electrons in such a way that each atom should get 8 electrons around it.
Resonance structures of formate ion:
What is the largest number
(of a single species) a specific area can support?
A. Population
B. Unlimited factor
C. Carrying capacity
D. Niche
Answer:
carrying capacity
Explanation:
Thus, the carrying capacity is the maximum number of individuals of a species that an environment can support. Population size decreases above carrying capacity due to a range of factors depending on the species concerned, but can include insufficient space, food supply, or sunlight.
The number of periods/series in Mendeleev's Periodic table is
A. 10
B. 13
C. 12
D. 14
Answer: The number of series in Mendeleev's Periodic table is 12.
Explanation:
Horizontal rows present in the periodic table are called periods. Vertical rows in the periodic table are called series.
Mendeleev gave periodic table in the year 1869 by arranging elements according to their atomic weights a in tabular form.
Mendeleev's periodic table depicts 12 periods/series.
Thus, we can conclude that the number of periods/series in Mendeleev's Periodic table is 12.
Choose the substance with the higher entropy in each pair. Assume constant temperature, except in part (5)
(i) 1 mol of SO2(g) or 1 mol of SO3(g)
(ii) 1 mol of CO2(s) or 1 mol of CO2(g)
(iii) 3 mol of O2(g) or 2 mol of O3(g)
(iv) 1 mol of KBr(s) or 1 mol of KBr(aq)
(v) Seawater at 2°C or at 23°C
(vi) 1 mol of CF4(g) or 1 mol of CCl4(g)
Answer:
I) 1 mol of SO3(g)
2) 1 mol of CO2(g)
3) 3 mol of O2(g)
4) 1 mol of KBr(aq)
5) Seawater at 23°C
6) 1 mol of CCl4(g)
Explanation:
In molecules having greater numbers of atoms, there is an increase the number of ways by which the molecule vibrates thereby leading to a higher number of possible microstates and overall increase in entropy of the system. Hence, 1 mol of SO3(g) has a higher entropy than 1 mol of SO2.
Gases have a higher entropy than liquids and liquids have a higher entropy than gases.
Also, the greater the molecular weight of a molecule, the higher the entropy. Higher number of moles of a gas as well as the increase in temperature of a substance are also factors that lead to higher entropy.
Methanal is the simplest aldehyde, with one carbon atom. Draw the structural model for methanal (using C and H).
[tex] {\bold{\red{\huge{\mathbb{QUESTION}}}}} [/tex]
Draw the structural model for methanal (using C and H and O).
[tex] \huge\mathbb{\red A \pink{N}\purple{S} \blue{W} \orange{ER}}[/tex]
First place the C and then make a double bonded O atom with it then fill H to complete all valence spaces
What do phase diagrams demonstrate?
Select all that apply.
how the melting and boiling points of a substance change with pressure
how much heat will increase the temperature of a gram of a substance by 1°C
the pressure and temperature conditions in which a substance exists as a liquid, solid, or gas
a comparison of the temperature of a substance to the heat absorbed over time
Answer:
this answer is for first one
Explanation:
A higher evalations, where the atmospheric pressure is much lower, the boiling point increase with increased pressure up to the critical point where the gas and liquid properties become identical
In water, Vanillin, C8H8O3, has a solubility of 0.070 moles of vanillin per liter of solution at 25C. What will be produced if 5.00 g of vanillin are added to 1 L of water at 25 C?
Answer:
The full amount (5.00 g) will be dissolved in 1 L of water at 25°C.
Explanation:
The molecular weight (MW) of Vanillin (C₈H₈O₃) is calculated from the chemical formula as follows:
MW(C₈H₈O₃) = (12 g/mol x 8) + (1 g/mol x 8) + (16 g/mol x 3) = 152 g/mol
If 0.070 mol of C₈H₈O₃ are soluble per liter of water at 25°C, the maximum mass that can be dissolved in 1 L is:
0.070 mol x 152 g/mol = 10.64 g
Since 5.00 g is lesser than the maximum amount that can be dissolved (10.64 g), the added amount will be completely dissolved in 1 L of water at 25°C.
Enter a balanced equation for the reaction between solid nickel(II)(II) oxide and carbon monoxide gas that produces solid nickel and carbon dioxide gas. Express your answer as a chemical equation. Identify all of the phases in your answer.
Answer: A balanced equation for the given reaction is [tex]NiO(s) + CO \rightarrow Ni(s) + CO_{2}(g)[/tex].
Explanation:
The reaction equation will be as follows.
[tex]NiO(s) + CO \rightarrow Ni(s) + CO_{2}(g)[/tex]
Number of atoms on the reactant side is as follows.
O = 2C = 1Number of atoms on the product side is as follows.
Ni = 1O = 2C = 1Since number of atoms on both the reactant and product sides are equal. Hence, the reaction equation is balanced.
Thus, we can conclude that a balanced equation for the given reaction is [tex]NiO(s) + CO \rightarrow Ni(s) + CO_{2}(g)[/tex].
Match the description with the type of precipitation being described.
1. Its formation requires very strong updrafts
2. Its formation requires falling through a layer of above freezing air
3. Precipitation from cumuliform clouds is typically of this nature
4. Precipitation from stratus clouds is typically of this nature
Options:
a. Hail
b. Drizzle
c. Shower
d. Freezing Rain
Answer:
1. Its formation requires very strong updrafts = a. Hail
2. Its formation requires falling through a layer of above-freezing air = d. Freezing Rain
3. Precipitation from cumuliform clouds is typically of this nature = c. Shower
4. Precipitation from stratus clouds is typically of this nature = Drizzle
Explanation:
Hail formation requires very strong updrafts, these updrafts are the upward moving air created in a thunderstorm. This period of noticeable thunderstorms creates hails.
Freezing rain requires the presence of warm air, it requires falling through a layer of above-freezing air to the colder air below to produce an ice coating on anything it drops on.
Showers are produced by cumuliform clouds which look like cotton balls. Since cumuliform clouds precipitate too, these clouds can have fluctuating rain in a day in the form of showers.
Drizzle which raises low visibility is considered a type of liquid precipitation since it also falls from a cloud. Drizzle which is obviously smaller in diameter when compared to that of raindrops, however, is common with stratus clouds.
If mass of an empty 9.4 mL pycnometer is 10.3 and the mass of the same pycnometer with an unknown liquid is 20.1. Determine the density of the unknown liquid to the correct number of significant figures in g/mL
Answer:
1.04 g/mL
Explanation:
Applying,
D = (m-m')/V................. Equation 1
Where D = Density of the unknown liquid, m = mass of the pycnometer when filled with unkwon liquid, m' = mass of the empty pycnometer, V = volume of the empty pycnometer
From the question,
Assuming the mass are in grams
Given: m = 20.1 g, m' = 10.3 g, V = 9.4 mL
Substitute these values into equation 1
D = (20.1-10.3)/9.4
D = 9.8/9.4
D = 1.04 g/mL
An electron-dot structure is a convenient method of representing
A. The complete electron configuration of the atom.
B. all electrons of the atom.
C. valence electrons of an atom.
D. core electrons of an atom.
Answer:
all electrons of the atom
According to Newton's law of universal gravitation, how do the masses of two
objects relate to the gravitational force between them?
A. As either mass increases, the gravitational force between them
increases.
B. As either mass increases, the gravitational force between them
decreases.
C. Gravitational force increases only when both masses increase.
D. Gravitational force increases only when both masses decrease.
Answer:
As either mass increases, the gravitational force between them
increases.
Explanation:
According to Newton's law of universal gravitation;
F α m1m2/r^2
That is, the force between two masses in a gravitational field is directly proportional to the product of the two masses and inversely proportional to their distance apart.
Hence, as either of the masses increase, the force of gravitation between the two masses increases. Hence the answer.
Question 5: Energy Sources (12 points)
A. There are many ways to produce electricity. List two energy sources that generate electricity via a chemical reaction, and explain what kind of reaction each uses. (6 points)
B. Ethane is a common component of energy sources. Write the chemical formula for ethane. (2 points)
C. Write and balance the chemical equation for the combustion reaction of ethane. (4 points)
Answer:
See explanation
Explanation:
It is possible to generate electricity through a chemical reaction in two ways;
I) use of a voltaic cell where spontaneous chemical processes produce electrical energy.
ii) use of an electrolytic cell where non spontaneous chemical processes produce electrical energy.
The chemical formula of ethane is C2H6
The balanced chemical equation for the combustion of ethane is as follows;
C2H6 + 7/2 O2 ------> 2CO2 + 3H2O
Increasing the temperature of a chemical reaction usually increases greatly the rate of the reaction. The most iportant reason for this is that increasing the temperature increases: _______.
A) the collision frequency
B) the probability factor
C) the fraction of collisions with energy greater than Bact
D) the energy of activation.
E) the amount of heat released in the reaction
Answer:
the fraction of collisions with energy greater than Eact
Explanation:
The activation energy of a reaction stands as a sort of energy barrier between reactants and products. It is only reactants that possesses energy greater than the activation energy that can be converted from reactants to products.
When the temperature of the system is increased, more particles acquire energy greater than the activation energy. Hence, the fraction of collisions with energy greater than the activation energy increases so the rate of reaction increases likewise.
