Answer:
Cr ^ 3 +
Explanation:
Recordemos que el número atómico es el número de protones en el núcleo del átomo. También corresponde al número de electrones en el átomo neutro.
Dado que el número de protones es 24, entonces el elemento debe ser cromo.
Si hay 21 electrones presentes, entonces se deben haber perdido 3 electrones para dar Cr ^ 3 +.
During a process called photoact, ________ give up an electron as a part of the light-dependent reactions.
Answer:
Chloroplasts?
Explanation:
The charge on a charged sphere is concentrated at (or on) its ________.
Central Core
Interior
Surface
I ANSWERED IT BUT SOMEONE SYAYS ITS COPY SO WHAT COULD I DO ;(
Answer:
The charge on a charged sphere is concentrated at (or on) its central core .hope it is helpful to you
A UV wave has a smaller___
than visible light.
Answer:
wavelength
Explanation:
i need to know the answer ASAP PLEASE
Answer:
E....H+
Explanation:
coz when hydrogen ions are formed they automatically join to form hydrogen
Someone please do a True or false of all of these
Answer:
1. False
2. True
3. False
4. False
5. True
6. False
7. True
8. True
9. True
An ice cube melting is a physical change b. An ice cube melting is a chemical change c. Paper burning is a physical change d. Paper burning is a chemical change e. Bubbles forming when soda pop is poured into a glass is a physical change f. Bubbles forming when soda pop is poured into a glass is a chemical change g. Hard-boiling an egg is a physical change h. Hard-boiling an egg is a chemical change
Answer:
An ice cube melting is a physical change because melting doesn't change the composition of the element. Paper burning is a chemical change because combustion occurs. Bubbles forming in a soda does involve chemical changes. Hard-boiling an egg is a chemical change because the egg's composition changed.
How were the elements in the first periodic table arranged? O A. In order of atomic number B. Alphabetically by element name C. In order of date of discovery O D. In order of atomic mass
Answer:
in order of their atomic mass
The first periodic table created by Mendeleev was based on the atomic masses of elements. Later Mosely modified it based on the atomic number.
What is periodic table ?Periodic table is the classification of all the known elements based on their atomic number. There are 118 elements in periodic table now. They are classified into different groups and periods.
Mendeleev was first to create periodic table for the easy classification of elements. He classified elements based on their atomic masses. At that time there were only 60-65 elements discovered.
Later Mosley modified it to modern periodic table based on the increasing order of atomic number of elements. Therefore, the first arrangement was based on atomic masses.
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A 10.0 L balloon contains helium gas at a pressure of 655 mmHg. What is the final pressure, in millimeters of mercury, if the final volume is 13.8 L? Please show your work in order to receive credit.
Answer:
474. 64 mm Hg
Explanation:
P1 = 655 mm Hg V1 = 10 LP2 = ? V2 = 13. 8 Lusing Boyle's Law that is
P1. V1 = P2. V2
655 × 10 = P2 × 13. 8
[tex]P2 = \frac{655 \times 10}{13.8} [/tex]
P2 = 474. 64 mm Hg
Calculate the molarity of 198 g of barium iodide (Bal2) in 2.0 l of solution
Answer: The molarity of 198 g of barium iodide [tex](BaI_{2})[/tex] in 2.0 L of solution is 0.253 M.
Explanation:
Given: Mass = 198 g
Volume = 2.0 L
Molarity is the number of moles of solute present in liter of a solution.
Moles is the mass of a substance divided by its molar mass. So, moles of barium iodide (molar mass = 391.136 g/mol) is calculated as follows.
[tex]Moles = \frac{mass}{molar mass}\\= \frac{198 g}{391.136 g/mol}\\= 0.506 mol[/tex]
Now, molarity is calculated as follows.
[tex]Molarity = \frac{moles}{Volume (in L)}\\= \frac{0.506 mol}{2.0 L}\\= 0.253 M[/tex]
Thus, we can conclude that the molarity of 198 g of barium iodide [tex](BaI_{2})[/tex] in 2.0 L of solution is 0.253 M.
For a reaction, AH = 176 kJ/mol and A SO = 0.285 kJ/(K•mol). At what
temperatures is this reaction spontaneous?
A. At no temperature
B. T< 50 K
C. T>617 K
D. T< 617 K
Answer:
C. T>617 K
Explanation:
We are given that
[tex]\Delta H=176KJ/mol[/tex]
[tex]\Delta S=0.285KJ/K\cdot mol[/tex]
We have to find the temperature at which the reaction is spontaneous.
When
[tex]\Delta H>0, \Delta S>0[/tex]
Therefore, the reaction is spontaneous at certain range of temperature.
Option A is not true.
[tex]\Delta G=\Delta H-T\Delta S[/tex]
When [tex]\Delta G[/tex] is negative, then the reaction is spontaneous.
[tex]\Delta G=176-0.285T[/tex]
When T<50
Suppose T=49 K
[tex]\Delta G=176-49\times 0.285>0[/tex]
Therefore, [tex]\Delta G is positive[/tex].Hence, the reaction is not spontaneous.
Option B is wrong.
C.T>617K
Suppose T=618 K
[tex]\Delta G=176-0.285\times 618=-0.13<0[/tex]
Therefore, [tex]\Delta G is negative[/tex].Hence, the reaction is spontaneous.
So, option C is true.
D.T<617 K
Suppose T=616 K
[tex]\Delta G=176-0.285\times 616=0.44>0[/tex]
Therefore, [tex]\Delta G is positive[/tex].Hence, the reaction is not spontaneous.
So, option D is not true.
What is one characteristic that makes Earth capable of supporting life?
A. It has ocean currents that circulate water from pole to pole.
O B. It has a strong magnetic field that protects organisms from
harmful radiation.
C. It is in a solar system located in one of the outer arms of a spiral
galaxy
D. It has more mass than any of the other planets of the inner solar
system.
Answer:
it is option (d)
it has more mass than any of the other planets of the inner solar system
What are the basic elements of selection of proffesion?describe any two
Answer:
overall I think one answer
The molar mass of oxygen(O) is 32g. What is the mass of 1.05*10^25 molecules of O²
Answer:
Hope that will help you
Explanation:
Text me for more answers
A sodium atom has 11 protons and 12 neutrons. What is the mass number of this sodium atom?
Sodium has a mass number of 23amu. Since sodium has 11 protons, the number of neutrons must be 23 – 11 = 12 neutrons.
Atoms are:
O A. One of the 4 elements that matter is composed of.
B. Connected by bonds to form compounds.
OC. The basic building blocks of matter.
O D. Heterogeneous and refer to color, texture, and appearance.
Reset Selection
Answer:c
Explanation: atoms make matter
Atoms are the basic building blocks of matter. The correct option is C.
What are atoms?Atoms are the basic unit and building block of matter. They are the smallest unit, but they can be divided. They do not emit charge on dividing into the further, the smallest parts.
Atoms are further divided into electrons, protons, and neutrons. They are the charged particles that revolve in the shell of the atom. A nucleus is also present in the between of the atom.
Atoms are considered the building blocks of matter, as all matter is made up of many atoms. The configuration of the atom defines the state of matter.
Thus, the correct option is C. The basic building blocks of matter.
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please help me .........
solve it.
this is the the and*******to you and your team
Suggest two reasons why carbon dioxide emissions from electricity production decreased from 2012 to 2015
Answer:
global warming
Explanation:
Applying smart electric grid technologies can potentially reduce CO2 emissions.
How many ATOMS of boron are present in 3.61 grams of boron trifluoride ?
Hi there!
[tex]\large\boxed{3.203 * 10^{22} atoms}[/tex]
We can use the following conversions to solve:
Total mass --> amount of mols --> amount of atoms (Avogadro's number)
Begin by calculating the amount of boron trifluoride in 3.61 grams:
3.61 g * (1 mol BF₃ / 67.8 g) ≈ 0.0532 mol BF₃
Use avogadro's number to convert:
0.0532 mol * 6.02× 10²³atoms / 1 mol = 3.203 × 10²² atoms
How many atoms are there in 1 g of argon?
The Avogadro constant is 6.02 × 1023 per mole.
Relative atomic mass (Ar): Ar = 40
Answer:
1.5057×10^22 atom
Explanation:
As we
1 mole of argon = 40 g of argon
i.e 40 g of argon = 1 mole of argon
1 g of argon = 1/40 mole of argon
1 mole of argon = 6.023×10^23 atom of argon
1/40 mole if argon = 1/40 ×6.023×10^23
= 1.5057×10^22
The number of atoms of Argon in 1 g would be 1.51 × 10²²
To find out the number of atoms of Argon in 1 g of Argon, the number of moles has to be calculated from which the number of atoms can be derived.
The molecular mass of Argon is 40. The number of moles of Argon is calculated as:
Number of moles of Argon = [tex]\frac{Mass of Argon in grams}{Molecular mass of Argon}[/tex]
Substituting molecular mass as 40 and mass in grams as 1. we get:
Number of moles of Argon = [tex]\frac{1}{40}[/tex] = 0.025 mol
Number of atoms in 1 mole of any substance is given by Avogadro's number as 6.022 × 10²³.
Thus, number of atoms of Argon in 0.025 moles would be
= 0.025 × 6.022 × 10²³
= 0.151 × 10²³ or 1.51 × 10²²
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the stomach, small intestine, and large intestine are all organs. when they work together to process food, they form a functional unit known as
Answer:
Organ System
Explanation:
These organs are helping each other process food and therefore be an Organ System
Methane is the main component of natural gas. Using the given reaction enthalpy, calculate the heat energy produced by the combustion of one kilogram of methane.
Answer: The heat energy produced is 53831.25KJ
Explanation:
METHANE is the main component of natural gas. It can undergo combustion reaction in air with a bright blue flame to produce carbondioxide and water. The heat of reaction (enthalpy) is negative because heat is absorbed during the chemical reaction. To calculate the heat energy produced by the combustion of one kilogram (1 kg) of methane the following steps are taken:
Molecular mass of methane =16 gm/mol.
So moles of 1 kg methane =
Given mass of methane ÷ molecular weight of methane
But the given mass = 1kg = 1000g
Therefore,
moles of 1000g methane = 1000÷16
= 62.5 moles
Hence, energy evolved = (moles of methane) × (heat of combustion)
Therefore,
heat energy produced= 62.5 × (-861.3kj)
= -53831.25kj
The heat energy produced by the combustion of one kilogram of methane is –53831.25 KJ
We'll begin by calculating the number of mole in 1 Kg of CH₄
Mass of CH₄ = 1 kg = 1000 g
Molar mass of CH₄ = 12 + (4×1) = 16 g/mol
Mole of CH₄ =?Mole = mass /molar mass
Mole of CH₄ = 1000 / 16
Mole = 62.5 moles Finally, we shall determine the heat energy produced from the reaction.CH₄ + 2O₂ —> CO₂ + 2H₂O ΔH = –861.3 KJ
From the balanced equation above,
1 mole of CH₄ reacted to produce –861.3 KJ.
Therefore,
62.5 moles of CH₄ will react to produce = 62.5 × –861.3 = –53831.25 KJ
Thus, –53831.25 KJ of heat energy is produced.
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A solution of known concentration is called
Answer:
It is called standard solution.
Explanation:
I hope this helps! Have a nice dayy! :)
HELP ASAP Choose three sections of the electromagnetic spectrum. Rank them in order of energy. Give an example of how they are used for each.
Hello, if any of y'all don't mind, can one of you answer these 5 questions.
Answer:
4.. increases
5..lowers
6.. increases
7.. increases
8.. speed
Answer:
When a substance is heated, its temperature rises because its molecules move faster and gain thermal energy. Temperature measures the "hotness" or "coldness" of an object. The term heat refers to thermal energy being transferred from a hotter system to a cooler one.
What is a polyatomic compound?
What is a polyatomic compound?
➡A polyatomic ion is an ion that contains more than one atom. This differentiates polyatomic ions from monatomic ions, which contain only one atom.
#CarryOnLearninghow many distinct monochlorinated products can result when methylcyclohexane is subjected to free radical chlorination under UV light
Answer:
How many distinct monochlorinated products can result when methylcyclohexane is subjected to free radical chlorination under UV light.
Explanation:
Consider 1-methylcyclohexane:
Its structure is shown below:
It has primary [tex]1^o[/tex], secondary [tex]2^o[/tex]and tertiary [tex]3^o[/tex] carbons as shown in the image.
So, the following mono chlorinated product will be formed.
Help please! Given that the enthalpy of reaction for a system at 298 K is –292 kJ/mol and the entropy for that system is 224 J/mol*K, what's the free energy for the system?
a) -87,793 kJ
b) -225 kJ
c) -66,751 kJ
d) 358 kJ
Answer:
C. -66, 751 kjExplanation:
hope it helps
PLS HELP ASAPPP!!!
Compare and contrast an electrolytic cell with a voltaic cell. Provide one example where both are present in daily life.
Voltaic cells convert chemical energy to electrical energy by means of an oxidation-reduction reaction while Electrolytic cells convert electrical energy to chemical energy, so they are the opposite of voltaic cells,in an electrolytic cell, the cathode is negatively charged and the anode is positively charged
Answer:
ELECTROLYTIC CELL
An electrochemical cell in which a non-spontaneous chemical reaction takes place when electric current is passed through the solution,is called an electrolytic cell.
EXAMPLE
Nelsons cell and Downs cell
VOLTAIC CELL OR GALVANIC CELL
The electrochemical cell in which a spontaneous chemical reaction takes place and generates electric current is called galvanic and voltaic cell.
EXAMPLE
Daniel cell
Explanation:
Water is an amphoteric substance because it can receive and donate hydrogen ions.
- True
- False
Answer:
True
Explanation:
The answer is True...
Answer:
i think true
Explanation:
if right than tag me brilliant
Consider the following reaction, where A and
E are hypothetical elements.
A + 3E --> AE3
The atomic mass of A is 42.1 amu.
The atomic mass of E is 56.2 amu.
If 42.6 g of A fully reacts, how many grams of
AE3 are expected to form?
Enter your numerical answer to 1 decimal
place. Do not include the units of "g".
Answer:
Enter your numerical answer to 1 decimal place. Do not include the units of "g". Question: Question 14 1 pts Consider the following reaction, where A and E are hypothetical elements. A+3E --> AE The atomic mass of A is 42.1 amu. The atomic mass of Eis 56.2 amu. If 42.6 g of A fully reacts, how many grams of AE, are expected to form?