Answer:
20
Explanation:
Hi there!
We need to find the atomic number of an atom that has 20 protons and 20 neutrons
the atomic number of an atom is equivalent to the amount of protons an atom has, as the number of protons determines what element an atom is.
Since the atom has 20 protons, the atomic number of the said atom is 20
Hope this helps!
What is a rechargeable battery?
a group of electrochemical cells that can be recharged
a group of electrolytic cells that can be recharged
a group of electrochemical cells that do not need recharging
O a group of electrolytic cells that do not need recharging
WILL GIVE BRAINLIEST
Answer:
a group of electrochemical cells that can be recharged
The enthalpy of a reaction is -394 kJ/mol. How would you describe the
reaction?
A. Spontaneous
B. Exothermic
C. Endothermic
D. Nonspontaneous
Answer:
the reaction is spontaneous
use a periodic table to write the electron configuration of selenium
Answer: The electronic configuration of selenium is [tex]1s^22s^22p^63s^23p^64s^23d^{10}4p^4[/tex]
Explanation:
The atomic number is defined as the number of protons or number of electrons present in a neutral atom.
Number of electrons will be equal to the atomic number of an atom.
Electronic configuration is defined as the representation of electrons in an atom.
Selenium is the 34th element of the periodic table.
The electronic configuration of Selenium is [tex]1s^22s^22p^63s^23p^64s^23d^{10}4p^4[/tex]
It has 6 electrons that are present in the outermost shell.
hey armies.. how are you doing
Answer:
Nice and you
Explanation:
Please Mark me brainliest
You burn a log on a fire. You use fire to warm yourself and help you see to read a book. What energy transformation is taking place?
Answer:
heat energy to keep you warm and light energy to be able to read your book
Explanation:
What is one way to neutralize acidic lakes using an acid-base reaction?
[tex]\huge\fcolorbox{red}{pink}{Answer ♥}[/tex]
Solutions for Neutralization of Acidic Lakes. ... A common solution to increase water hardness in acid lakes is to add lime, a high-alkalinity calcium compound to the acid lakes. This method is only temporary and very expensive, as it often needs to be applied every year.
Hope it helps uh ✌️✌️
Balance equation for. _Mg + _H3(PO4) --_Mg3(PO4)2+ _H2
Determine the excluded volume per mole and the volume actually occupied by a mole for a gas consisting of molecules with radius 167 pm. [Note: To obtain the volume in liters, we must express the radius in decimeters (dm).] Enter your answers in scientific notation.
Answer:
Explanation:
Volume of one mole of a gas = 22.4 litre.
No of molecules in one mole of gas = 6.02 x 10²³ .
Volume of one molecule = 4/3 π R³
= 4/3 x 3.14 x ( 167 x 10⁻¹² m )³
= 19.5 x 10⁶ x 10⁻³⁶ m³
=19.5 x 10⁻³⁰ m³
= 19.5 x 10⁻³⁰ x 10³ litre .
= 19.5 x 10⁻²⁷ litre .
So volume occupied by molecules in one mole of gas
= 19.5 x 10⁻²⁷ x 6.02 x 10²³ litre
117.4 x 10⁻⁴ litre
= .01174 litre.
Excluded volume
= ( 22.4 - .01174 ) litre .
= 22.388 litre.
What pollutants can contribute to acid precipitation and how are these pollutants generated?
Answer:
Acid rain is caused by a chemical reaction that begins when compounds like sulfur dioxide and nitrogen oxides are released into the air. These substances can rise very high into the atmosphere, where they mix and react with water, oxygen, and other chemicals to form more acidic pollutants, known as acid rain.
hope it helps
stay safe healthy and happy...Sulfur dioxide and nitrogen oxides can contribute to acid precipitation.
What are pollutants?A pollutant is a chemical or biological substance which harms water, air, or land quality.
Acid rain is caused by a chemical reaction that begins when compounds like sulfur dioxide and nitrogen oxides are released into the air. These substances can rise very high into the atmosphere, where they mix and react with water, oxygen, and other chemicals to form more acidic pollutants, known as acid rain.
Learn more about the pollutants here:
https://brainly.com/question/16101020
#SPJ2
The weak base ionization
constant (Kb) for Clois
equal to:
A
B
[CIO-][H30+)
[HOCI]
[HCIO][OH-]
[CIO-]
Answer:
The answer would be [HCIO][OH-]
_________
[CIO-]
Explanation:
So, the answer would be (b).
Which drawing is structural model of C3H8?
Answer:
option B is the correct answer
Calculate the average atomic mass element X
Answer:
39.02 amu
Explanation:
The average atomic mass of an element can be calculated as follows :
[tex]X=\dfrac{9.67\times 38+78.68\times 39+11.34\times 40+0.31\times 41}{100}\\\\X=\dfrac{3902.29}{100}\\\\X=39.02\ amu[/tex]
So, the atomic mass of the element X is 39.02 amu.
Consider the balanced reaction below:
2HBr + Ba(OH)2 → BaBr2 + 2H2O
How many moles of barium
hydroxide, Ba(OH)2, would be
required to react with 117 g hydrogen bromide, HBr?
Answer:
0.723 moles (5 s.f.)
Explanation:
Whenever there is a chemical equation, ensure that it is balanced. This is because a balanced chemical equation tells us the mole ratio (not the ratio of their masses), which means the relationship of the number of moles of reactants or products with one another.
The chemical equation given has already been balanced. Looking at the coefficients of HBr and Ba(OH)₂, the mole ratio of HBr to Ba(OH)₂ is 2: 1.
• 1 mole of Ba(OH)₂ is needed to react with 2 mole of HBr
Find the number of moles of HBr present:
Number of moles= mass ÷mr
Amount of HBr
= 117 ÷(1 +79.9)
= 1.4462 moles (5 s.f.)
Since the amount of Ba(OH)₂ required is half the amount of HBr present,
amount of Ba(OH)₂ required
= 1.4462 ÷2
= 0.723 moles (3 s.f.)
Notes:
• mr
= relative molecular mass
= sum of relative atomic masses (which can be found in the periodic table) in a molecule
2. As NH4OH is added to an HCl solution, the pH of the solution
A) increases as the OH- concentration decreases
B ) increases as the OH- concentration increases
C ) decreases as the OH- concentration decreases
D ) decreases as the OH- ion concentration increases
Answer:
c
Explanation:
Nh4OH + HCL ---> NH4Cl + H3O
so ph decreases as H3O increases
and OH also decreases
When NH4OH is added to a solution with HCI, the pH of the solution B ) increases as the OH- concentration increases.
Why would the solution increase?NH₄OH is a strong base as a result of the presence of the OH compound which is a base as well. Bases have high pH and acids have low pH.
This means that as the OH- concentration increases, the solution is being made to be more basic which would lead to the pH rising.
In conclusion, option B is correct.
Find out more on Bases at https://brainly.com/question/15565260.
Q2.
This question is about metals and metal compounds.
(a)
Copper oxide reacts with hydrochloric acid to produce copper chloride and water.
Copper oxide is insoluble in water.
Copper oxide is gradually added to hydrochloric acid until in excess.
Magnesium reacts with hydrochloric acid to produce magnesium chloride and hydrogen.
Plan an investigation to find the accurate volume of hydrogen produced from
magnesium
You do not need to write about safety precautions.
Answer:
sry I don't know the answer
Which statements are consistent with Dalton"s atomic theory as it was originally stated? Why? a. Sulfur and oxygen atoms have the same mass. b. All cobalt atoms are identical. c. Potassium and chlorine atoms combine in a 1:1 ratio to form potass...
The question is incomplete, the complete question is:
Which statements are consistent with Dalton's atomic theory as it was originally stated? Why?
a. Sulfur and oxygen atoms have the same mass.
b. All cobalt atoms are identical.
c. Potassium and chlorine atoms combine in a 1:1 ratio to form potassium chloride.
d. Lead atoms can be converted into gold.
Answer: The correct options are b) and c).
Explanation:
Some of the postulates of Dalton's atomic theory are:
All matter is made of very tiny particles called atoms that participate in chemical reactionsAtoms are indivisible particles that cannot be created or destroyed in a chemical reactionAtoms of a given element are identical in mass and chemical propertiesAtoms of different elements have different masses and chemical properties.Atoms combine in the ratio of small whole numbers to form compounds.The relative number and kinds of atoms are constant in a given compound.For the given options:
For a:
The statement is inconsistent with the theory as no two elements can have the same mass. Only atoms of the same element can have the same mass.
For b:This is consistent with the theory as atoms of the same element are identical.
For c:This is consistent with the theory as atoms combine in a simple whole number ratio.
For d:The statement is inconsistent with the theory as atoms of one element cannot be changed to atoms of other element.
Hence, the correct options are b) and c).
9. During a titration, 50.0 ml of 0.2M NaOH were required to neutralize 50.0ml of H_{3}*P * O_{4} What's the concentration of the H_{3}*P * O_{4} solution?
Answer:
0.067M H3PO4
Explanation:
H3PO4 reacts with NaOH as follows:
H3PO4 + 3NaOH → 3H2O + Na3PO4
Where 1 mole of H3PO4 reacts with 3 moles of NaOH
To solve trhis question we need to find the moles of NaOH required. With the chemical equation we can find the moles of H3PO4 and its concentration as follows:
Moles NaOH:
50.0mL = 0.0500L * (0.20moles /L) = 0.0100 moles NaOH
Moles H3PO4:
0.0100 moles NaOH * (1mol H3PO4 / 3mol NaOH) = 0.00333 moles H3PO4
Concentration:
0.00333 moles H3PO4 / 0.0500L = 0.067M H3PO4
What is the salt produced in the stomach when calcium carbonate reacts with and neutralizes excess hydrochloric acid?
The salt CaCl2 (calcium chloride) and water (H2O) are formed in this reaction. Also formed is the gas carbon dioxide (CO2) which may cause a bloated feeling in the stomach. The acid that is secreted in your stomach is approximately 0.1 M (moles per liter) hydrochloric acid.
I hope it helps ●~●
What is the symbol for an ion with a 3+ charge, 28 electrons, and a mass number of 71
Answer:
Ga3+ is a gallium cation
HELP PLSSS WOOT WOOT
Coupled reactions are: A. reactions in which endergonic reactions obtain the energy to go forward from exergonic reactions. B. reactions in which exergonic reactions obtain the energy to go forward from endergonic reactions. C. reactions that lower the activation energy of another reaction. D. any reactions that are accelerated by an enzyme.
Answer:
A
Explanation:
Coupled reactions are reactions in which endergonic reactions obtain the energy to go forward from exergonic reactions.
When benzene diazonium chloride interacts with phenol, the para position of the phenol molecules is associated with the diazonium salt, resulting in
p-hydroxyazobenzene. The coupling reaction is the name given to this process.
List twelve types of industry
Answer:
-Aerospace Industry.
-Transport Industry.
-Computer Industry.
-Telecommunication industry.
-Agriculture industry.
-Construction Industry.
-Education Industry.
-Pharmaceutical Industry.
-Food Industry
-Health Care Industry
-Hospitality Industry
-Entertainment Industry
Which of the following units is not an official SI unit?
a) kilogram
b) ampere
c) mole
d) liter
Answer:
liter
Explanation:
I think liter because it is not listed as a SI unit
Answer:
[tex]{ \bf{d). \: { \tt{litre}}}}[/tex]
How many moles of sodium carbonate in 18.06x10 to the power 22
Answer:
[tex] moles = \frac{ number \: of \: particles}{6.02 \times {10}^{23} } [/tex]
=1.806×10^22/6.02×10^23
=0.03 moles
hope this helps :)
El simbolo del ion que contiene 24 protones, 28 neutrones y 21 electrones es : A)Sc+3 B)Sc-3 C)Sc D)Cr E)Cr-3
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 +.
To make a sarurated solution, 36 g of sodium chloride is dissolved in 100 g of water at 293 k . Find its concentration at this temperature
Answer:
The answer is "[tex]26.47\%[/tex]"
Explanation:
Sodium chloride solute mass[tex]=36 \ g[/tex]
Solvent water mass[tex]=100\ g[/tex]
Calculating the solution mass = Solute mass + solvent mass
[tex]= 36\ g +100\ g\\\\ = 136\ g\\\\[/tex]
Calculating the percentage of concentration:
[tex]= \frac{solute\ mass}{solvent\ mass} \times 100\\\\=\frac{36\ grm}{136\ grm} \times 100\\\\=0.2647 \times 100\\\\=26.47 \%[/tex]
1. All of the following statements are true
regarding spontaneous process, EXCEPT:
A. It occurs without requiring an outside
force.
B. It can be a physical or chemical change
C. It will continue until equilibrium is
reached.
D. It will suddenly stop once products ar
formed.
Which of the following is an example of a
spontaneous process?
A. Melting of ice in room temperature
B. Transfer of heat from a cold objectt
hot object
C. Removing rust on an iron nail
D. Separation of hydrogen and oxygen
atoms via electrolysis
Answer:
ïgGshdhdhdhdhdbdhdhdjddk
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.
How many bonds can a carbon atom form?
O A. 1
B. 2
C. 4
O D. 3
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
