Answer:
B. 20, 22, 20
Explanation:
The atomic number (Z) of calcium is 20, that is, it has 20 protons.
The mass number (A) of calcium-42 is 42. The mass number is equal to the sum of protons and neutrons. Then,
p⁺ + n⁰ = 42
n⁰ = 42 - p⁺
n⁰ = 42 - 20
n⁰ = 22
Since calcium is electrically neutral, it has the same number of protons (+) and electrons (-). Then, calcium has 20 electrons.
Based on the chemical equation, use the drop-down menu to choose the coefficients that will balance the chemical equation:
(
)BaO2 + (
)H2SO4 → (
)H2O2 + (
)BaSO4
Answer:
1
1
1
1
Explanation:
the equation is balancing
find the number of hydrogen atoms of an alkyl group with 2 carbon atoms if n=2
Answer:
5
Explanation:
An alkyl group is a functional group that contains only hydrogen and carbon atoms. It has the general formula: CnH2n+1.
Since n=2, plug it into the formula.
C2H2(2)+1
=
C₂H₅
Hope that helps.
Pure sodium metal reacts violently with water according to the equation below
Na + H2O - NaO + H2
17 mol
If 0.75 mol of Na is placed in 500 g of
H,O how many moles of hydrogen
gas will be produced?
0.75 mol
28 mol
1.5 mol
Answer:
0.75 mol
Explanation:
Given data:
Number of moles of Na = 0.75 mol
Mass of water = 500 g
Moles of hydrogen gas produced = ?
Solution:
Chemical equation:
Na + H₂O → NaO + H₂
Number of moles of water:
Number of moles = mass/molar mass
Number of moles = 500 g/ 18 g/mol
Number of moles = 27.8 mol
now we will compare the moles of hydrogen gas with both reactant.
Na : H₂
1 : 1
0.75 : 0.75
H₂O : H₂
1 : 1
27.8 : 27.8
sodium will act as limiting reactant it produced small number of moles of hydrogen gas as compared to water.
Thus, number of moles of hydrogen gas are 0.75 mol.
Rosie balanced the equation below with the lowest coefficients, however she made a mistake.
2 AgCl + 2 Mg(NO3)2 --> 1 AgNO3 + 2 MgCl2
What was her error and what should the correct answer be?
Answer:
2 AgCl + Mg(NO3)2 --> 2AgNO3 + MgCl2
Explanation:
This is balanced equation
Which one is true? Elements in the same row have the same number of:
Explanation:
Elements in same row (i.e, from left to right) have the same number of electron shells.
What would have a higher boiling point water or hydrocarbon ( from penny liquid stacking)
Answer:
Im pretty sure its hydrocarbon
Explanation:
g In this equation stands for the Rydberg energy, and stands for the principal quantum number of the orbital that holds the electron. (You can find the value of the Rydberg energy using the Data button on the ALEKS toolbar.) Calculate the wavelength of the line in the emission line spectrum of hydrogen caused by the transition of the electron from an orbital with to an orbital with . Round your answer to significant digits.
The complete question is attached to this answer
Answer:
2.75 * 10^-5 m
Explanation:
The energy of the absorbed photon = ΔE
ΔE = - Ry (1/n^2 final - 1/n^2initial)
Given that Ry = 2.18 *10^-18 J
nfinal = 9
ninitial =8
ΔE = - 2.18 *10^-18 (1/9^2- 1/8^2)
ΔE = - 2.18 *10^-18 (0.0123 - 0.0156)
ΔE = 7.194 * 10^-21 J
But
ΔE =hc/λ
h = 6.6 *10^-34Js
c= 3 * 10^8 ms-1
λ= the unknown
λ= hc/ΔE
λ= 6.6 *10^-34 * 3 * 10^8/ 7.194 * 10^-21
λ= 2.75 * 10^-5 m
A sample is in the second half-life. What percent of the sample is stable at this point?
A. 12.5%
B. 25%
C. 50%
D. 75%
Answer:
75%
Explanation:
on edg :)
Two models of the same compound are shown.
On the left labeled Model A 2 large overlapping black spheres with 3 small blue spheres overlapping the rear black sphere and 2 medium red spheres overlapping the front black sphere. One of the red spheres has a small blue sphere overlapping it. On the right labeled Model B 2 C's connected by a black line. The C on the left has 3 H's attached by 1 black line each and the C on the right has 2 Os attached to it. The top O is attached by 2 black lines and the bottom O by 1 black line. The bottom O also has an H attached to it by 1 black line.
In what way is Model A better than Model B?
Model A shows the types of elements in the compound, but Model B does not.
Model A shows the total number of atoms in the molecule, but Model B does not.
Model A shows the three-dimensional shape of the molecule, but Model B does not.
Model A shows the number of atoms of each element in the molecule, but Model B does not.
Answer: C. Model A shows the three-dimensional shape of the molecule, but Model B does not.
Explanation:
i took the test and it makes the most sence for the modeles.
Amino acids are the building blocks of proteins. The simplest amino acid is glycine (H2NCH2COOH). Draw a Lewis structure for glycine. (Hint: The central atoms in the skeletal structure are nitrogen bonded to carbon, which is bonded to another carbon. The two oxygen atoms are bonded directly to the right-most carbon atom.) Draw the molecule by placing atoms on the grid and connecting them with bonds. Include all hydrogen atoms and nonbonding electrons.
Answer:
Explanation:
The lewis structure (indicating all the atoms and patterns provided as hint in the question) of glycine can be seen in the attachment below. While the chemical structure of glycine can be seen below
H
|
H₂N - C - C =O
| \
H OH
The structure (of glycine) above provides a "fair idea" of how the lewis structure will be.
According to the collision theory, which is required for a high number of effective collisions? a very low amount of force from colliding molecules a very low amount of kinetic energy from colliding molecules molecular collisions that have very specific orientations molecular collisions with energy to overcome activation energy
Answer:
the answer is D
Explanation:
i answered c and got it wrong on edg... i hope this helps :)
According to the collision theory, molecular collisions that have very specific orientations are required for a high number of effective collisions.
What is collision theory?Collision theory is used to predict the rates of chemical reactions, particularly for gases.
Based on the collision theory, a high frequency of effective collision is dependent on the molecular collisions that have very specific orientations.
The collision theory suggests that for reactions to occur, there must collision between reacting particles.
The number of collision is dependent on the number of collision per unit time as well as fractions of effective collision.
To attain effective collision, colliding particles must be properly oriented to give the desired product.
Hence, option C is correct.
Learn more about collision theory here:
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Question 1 (3 points)
(01.01 LC)
Which of the following objects will exert the greatest gravitational force on a box, if the distance between them remains the same? (3 points)
Оа
2 kg mass
Ob
4 kg mass
Ос
6 kg mass
8 kg mass
The following objects will exert the greatest gravitational force on a box⇒ 8 kg mass
Further explanationGravity is a force that arises because of the attraction between objects with mass.
The magnitude of this attraction is proportional to the mass of the object.
The greater the mass of the object, the greater the gravitational force
Relationships can both be stated in
Newton's Gravity Law:
[tex]\rm F=G.\dfrac{m_1.m_2}{r^2}[/tex]
with F = gravitational force,
G = gravitational constant,
m1, m2 = mass of object,
r = distance between two objects.
The distance-r and mass of the box(m₁) are the same, then the largest object's mass (m₂)exerts a large gravitational force, because the gravitational force is directly proportional to the mass of the two objects
PLEASE HELP WILL GIVE BRAINLIEST
Answer: B
We use stoichiometric amounts of P4 and PH3
NO.9) It's actual yield
please help me i will give brain list
Answer:
a. pentane = C5H12
b. Heptane = C7H16
c. Hexyne = C6H10
d. Octene = C8H16
e. Nonane = C9H20
Hope it helps.
1-pentene
Molecular Formula C5H10
Condensed Structural FormulaCH2=CH(CH2)2CH3
Melting Point (°C)–138
Boiling Point (°C)30
2- heptane is the straight-chain alkane with the chemical formula H3C(CH2)5CH3 or C7H16, and is one of the main components of gasoline (petrol).
Please answer it truthfully please
Answer:
False
Explanation:
Chemical and Physical changes happen uniquely, they cannot happen at the same time. When you crumble a piece of paper you don't change its chemical form you change its physical form. When a piece of metal rusts its chemical composition changes, leading me to believe it is false.
Good luck on the rest of your assignment/test!
The Lewis diagram for BH2 is:
[H-B-H]-
The electron- pair geometry around the B atom in BH2 is:__________.
There are______lone pair(s) around the central atom, so the geometry of BH2 is________ .
Answer:
Electron pair geometry- trigonal planar
There is one lone pair around the boron atom
The geometry of BH2 is bent
Explanation:
The valence shell electron pair repulsion theory offers a frame work for determining the shape of molecules based on the number of electron pairs of the valence shell of the central atom in the molecule.
In BH2-, the central atom is boron. There is a lone pair on boron. Owing to the lone pair on boron, the molecular geometry of BH2 is bent.
The geometry of the electron pair around the Boron atom in [tex]BH_2[/tex] is called the trigonal planar. In this case, there is a pair of isolated electrons around Boron, which is the central atom, allowing the [tex]BH2[/tex] molecule to have a folded geometry.
We can arrive at this answer because:
Boron is an element that has three electrons in its valence layer.With this, we can find out that it can make three covalent bonds or donate these electrons to achieve chemical stability.In the case of the [tex]BH_2[/tex] molecule, boron forms covalent bonds with Hydrogen.These bonds allow the Hydrogens to be positioned on either side of the Boron molecule, forcing a pair of their electrons to focus on the center of that molecule, until it is attracted to the extremities.This allows for a folded geometry around the molecule, allowing Boron to be an exception to the octet rule and achieve stability with 5 electrons in the valence layer.
More information:
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Which of the following is NOT a property of sodium
1. Sodium is a reactive METAL
2. Sodium is very SOFT
3. Sodium is a reactive GAS
4. Sodium forms a WHITE coating
Answer:
3
Explanation:
Sodium is not a gas, it is a Alkali Metal. I recommend studying the sections of the periodic table to help remember what each element should be.
Hope this helps.
HELPPPPPP
is this
1:conduction
2:radiation
3:convection
Answer:
Radiation
Explanation:
Sun rays shine on earth. Thats radiation.
Which electron dot diagram represents H2?
Answer:
H:H
Explanation:
Which best defines a service? a task that is performed in exchange for payment an object that is acquired a plan that is executed an image that is drawn
Answer:
a task that is performed for payment
Explanation:
all of the other answers do not pertain to the question
A service is best defined as a task that is performed in exchange for payment.
What is a task?A task is an activity that needs to be accomplished within a defined period of time or by a deadline to work towards work-related goals, usually done in exchange for payment.
Thus, we can conclude that, a service is best defined as a task that is performed in exchange for payment.
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which is the product of cellular respiration?
Answer:
I'm pretty sure the answer is ATP
Explanation:
Answer:
A. ATP
To be more specific, 38 ATP is the product of cellular respiration
Explanation:
Suppose you wish to determine the order of the reaction. You initially measure a rate, r0, given some arbitrary concentration of reactants. You then proceed to double the amount of A in the reaction (keeping B the same) and find that the rate is now 2r0. In a reciprocal experiment, you double the amount of B (A same as initial) in the reaction and measure a rate of 8r0. What is the order of this reaction
Answer:
See explanation
Explanation:
Now taking A, we can see that if we double the amount of A while keeping the amount of B constant, the rate of reaction doubles, hence we can write;
2^n = 2^1
hence n =1
For B, when the amount of B is doubled while keeping the amount of A constant, the rate of reaction increases eight times. Hence we can write;
2^n = 8
2^n = 2^3
n=3
Hence this reaction has an overall order of 1 + 3 = 4
So we can write;
rate =k[A] [B]^3
Please help....thank you
Answer:
a. volcanic changes create new land
Based on the principle of complementary colors, which colors or wavelengths of light would you expect to be most strongly absorbed by Cu2 ions?
Answer:
Red and Orange
Explanation:
Complementary colors are those colours located across from each other on a color wheel. If we look at the colour wheel attached to this answer, we will see various complementary colours shown.
A good look at the attached colour wheel reveals that blue Cu2+ ions absorbs light around the red and orange portions of the visible spectrum.
. A student adds 50 mL of Lead (II) Nitrate solution to 50 mL of potassium iodide. Each
solution is colorless, but when these two liquids are mixed, a yellow precipitate is
observed. What has most likely happened in the experiment?
Answer:
after the reaction between Lead (II) Nitrate solution and potassium iodide occur Lead(II) iodide was formed and it's yellow color.
Explanation:
Pb(NO3)2 + KI = KNO3 + PbI2
What else is produced when sodium carbonate decomposes?
Na2Co3 - Na2O+
Answer:When a single compound breaks down into two or more compounds or elements in a chemical reaction then it is known as decomposition reaction.
The chemical symbol for sodium carbonate is .
The decomposition of sodium carbonate is:
The decomposition of sodium bicarbonate, will result in the formation of sodium oxide, and carbon dioxide, .
Hence, carbon dioxide, will produce with sodium oxide, on decomposition of .
Explanation:Na2CO3 Na2O +CO2 CO2 is the answer
Name one way that the scientific community has honored Mendeleev’s contribution to science.
Answer:
Mendeleev's greatest contribution to science is certainly the Periodic Table of Elements, which says the properties of basic elements repeat periodically when they are arranged by their atomic number. He made the discovery in 1869 during his work on the award-winning textbook on chemistry basics.
Inventions: Periodic table, Pyrocollodion
Explanation:
*Hope this helps*
Answer:
Mendeleev's greatest contribution to science is certainly the Periodic Table of Elements, which says the properties of basic elements repeat periodically when they are arranged by their atomic number. He made the discovery in 1869 during his work on the award-winning textbook on chemistry basics.
Inventions: Periodic table, Pyrocollodion
Explanation:
Bruh I hate science Pls help me
List 5 physical properties of matter.
What is a chemical property?
List 2 chemical properties.
What is the difference between chemical property and chemical change?
List 3 products that are the results of chemical reactions.
Answer:
1. The properties of matter include any traits that can be measured, such as an object's density, color, mass, volume, length, malleability, melting point, hardness, odor, temperature, and more.
2. A chemical property is a characteristic of a particular substance that can be observed in a chemical reaction.
3. Toxicity and acidity.
4. A chemical property describes the ability of a substance to undergo a specific chemical change. A chemical reaction is a process that occurs when one or more substances are changed into one or more new substances.
5. The five basic types of chemical reactions are combination, decomposition, single-replacement, double-replacement, and combustion. Analyzing the reactants and products of a given reaction will allow you to place it into one of these categories. Some reactions will fit into more than one category.
Hope this helps you~
How many moles are present in 2.126 g of H2O2 ?
Answer:
molecular weight of H2O2 or grams. This compound is also known as Hydrogen Peroxide. The SI base unit for amount of substance is the mole. 1 mole is equal to 1 moles H2O2, or 34.01468 grams.
1 grams H2O2 is equal to 0.029399071224542 mole.
1 grams H2O2 to mol = 0.0294 mol
10 grams H2O2 to mol = 0.29399 mol
20 grams H2O2 to mol = 0.58798 mol
30 grams H2O2 to mol = 0.88197 mol
40 grams H2O2 to mol = 1.17596 mol
50 grams H2O2 to mol = 1.46995 mol
100 grams H2O2 to mol = 2.93991 mol
200 grams H2O2 to mol = 5.87981 mol
There are 0.0625mol in 2.126 g of H2O2.
HOW TO CALCULATE MOLES:
The number of moles of a substance can be calculated by dividing the mass of the substance by its molar mass. That is;no. of moles (mol) = mass (g) ÷ molar mass (g/mol)According to this question, 2.126 g of H2O2 were given. The number of moles of H2O2 can be calculated as follows:Molar mass of H2O2 = 1(2) + 16(2)= 2 + 32
= 34g/mol
no. of moles = 2.126g ÷ 34g/molno. of moles = 0.0625molTherefore, there are 0.0625mol in 2.126 g of H2O2..Learn more at: https://brainly.com/question/21085277?referrer=searchResults
An angle of refraction is the angle between the refracted ray and the
incident ray.
normal.
medium.
boundary.
Answer:
Normal
Explanation:
with the boundary, is a glancing angle
with the incident ray, is the field of view
Answer:
B. normal
Explanation: