Answer:
10^-7.20 or 1×10^-7.20mol.dm^-3
Explanation:
[H3O^+]= -log[H3O^+]
=antilog(-pH)
=antilog(-7.20)
=10^-7.20 mol.dm^-3
Answer:
1.58 x 10^-7 M
Explanation:
Based upon the following diagram, propose a possible identity for atoms X and Y. Explain your answer in terms of the periodic table and ionic bonding. Lastly, explain why the atoms bond in this ratio.
Answer:
Up until now we have been discussing only the elemental forms of atoms which are neutrally charged. This is because the number of electrons (negative in charge) is equal to the number of protons (positive in charge). The overall charge on the atom is zero, because the magnitude of the negative charge is the same as the magnitude of the positive charge. This one-to-one ratio of charges is not, however, the most common state for many elements. Deviations from this ratio result in charged particles called ions.
Throughout nature, things that are high in energy tend to move toward lower energy states. Lower energy configurations are more stable, so things are naturally drawn toward them. For atoms, these lower energy states are represented by the noble gas elements. These elements have electron configurations characterized by full s and p subshells. This makes them stable and unreactive. They are already at a low energy state, so they tend to stay as they are.
The elements in the other groups have subshells that are not full, so they are unstable when compared to the noble gases. This instability drives them toward the lower energy states represented by the noble gases that are nearby in the periodic table. In these lower energy states, the outermost energy level has eight electrons (an “octet”). The tendency of an atom toward a configuration in which it possesses eight valence electrons is referred to as the “Octet Rule.”
There are two ways for an atom that does not have an octet of valence electrons to obtain an octet in its outer shell. One way is the transfer of electrons between two atoms until both atoms have octets. Because some atoms will lose electrons and some atoms will gain electrons, there is no overall change in the number of electrons, but with the transfer of electrons the individual atoms acquire a nonzero electric charge. Those that lose electrons become positively charged, and those that gain electrons become negatively charged. Recall that atoms carrying positive or negative charges are called ions. If an atom has gained one or more electrons, it is negatively charged and is called an anion. If an atom has lost one or more electrons, it is positively charged and is called a cation. Because opposite charges attract (while like charges repel), these oppositely charged ions attract each other, forming ionic bonds. The resulting compounds are called ionic compounds.
The second way for an atom to obtain an octet of electrons is by sharing electrons with another atom. These shared electrons simultaneously occupy the outermost shell of both atoms. The bond made by electron sharing is called a covalent bond. Covalent bonding and covalent compounds will be discussed in Chapter 4 “Covalent Bonding and Simple Molecular Compounds”.
At the end of chapter 2, we learned how to draw the electron dot symbols to represent the valence electrons for each of the elemental families. This skill will be instrumental in learning about ions and ionic bonding. Looking at Figure 3.1, observe the Noble Gas family of elements. The electron dot symbol for the Nobel Gas family clearly indicates that the valence electron shell is completely full with an octet of electrons. If you look at the other families, you can see how many electrons they will need to gain or lose to reach the octet state. Above, we noted that elements are the most stable when they can reach the octet state. However, it should also be noted that housing excessively high negative or positive charge is unfavorable. Thus, elements will reach the octet state and also maintain the lowest charge possible. You will note that for the IA, IIA, IIIA and transition metals groups, it is more economical to lose electrons (1-3 electrons) from their valence shells to reach the octet state, rather than to gain 5-7 electrons. Similarly main group columns VA, VIA, and VIIA tend to gain electrons (1-3) to complete their octet, rather than losing 5-7 electrons. Some atoms, like carbon, are directly in the middle. These atoms don’t like to gain or lose electrons, but tend to favor the sharing model of chemical bonding. The remaining sections of this chapter will focus on the formation of ions and the resulting ionic compounds.
Explanation:
which two terms best describe the level of organization of life shown in this photo?
Answer:
there's no photo, I'm sorry
Help me with this this is something i dont know and its not on here please help meeeeeee
Answer:
it would be option A
Explanation:
This is becuase if you look at the chart you can see tyhat the group of rats that got feed to vitamans did gain more wati then the ones on the normal diet.
How does adding heat energy affect magnesium fluoride (MgF2) molecules?
O A The motion of the molecules decreases.
o
B. The motion of the molecules increases.
O
C. The motion of the molecules is at a constant rate.
D. The motion of the molecules stops.
Answer:
Number B is Answer. The motion of the molecules increases
Please answer quickly!! 20 points!!9. Which represents the greatest mass of chlorine?
A) 1 mole of chlorine
B) 1 atom of chlorine
C) 1 gram of chlorine
D) 1 molecule of chlorine
Answer:
1 mole
Explanation:
if correct you may follow me for more helps
Among the given quantities, the greatest mass of chlorine is represented by one molecule of chlorine Cl₂ that is equal to 71 grams.
What is one molecules?A molecule of an element is formed by the combination of two atoms of that element. One mole of an element is the amount containing 6.022 × 10²³ atoms. This s number is called Avogadro number.
The mass of one mole of an element is called its atomic mass. Cl is 17th element. Atomic mass of Cl = 35.5 g
35.5 g of Cl is called one mole of Cl containing Avogadro number of atoms.
One molecule of Cl is represented as Cl₂ with the mass = 35.5 × 2 = 71 g.
This is the molecular mass of Cl.
One gram of Cl is small amount and mass of one atom of Cl is even smaller. Thus, one molecules of Cl represents the greater mass here. Hence, option D is correct.
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The period of development from fertilized egg to birth is known as
The period of development from fertilized egg to birth is known as [tex]{ \bf{ \underbrace{prenatal\: development}}}[/tex].
[tex]\bold{ \green{ \star{ \orange{Mystique35}}}}⋆[/tex]
PLEASE HELP THIS IS TIMED
Which of the following is a physical change?
CsF(s) + XeFo(s) → CsXeF;(s)
CO2 (s) + CO2(g)
O N2 (g) + 3H2 (g) → 2NH3 (g)
2H2 (g) + O2 (g) → 2H20 (1)
Zn(s) + 2 MnO2(s) + H20(1) → Zn(OH)2(s) + Mn2O3(s)
what are alpha particles??
Answer:
a helium nucleus emitted by some radioactive substances, originally regarded as a ray.
Explanation:
Answer:
They're charged particles Identical to the Helium Nucleus
Having 2 protons and 2neutrons and having a Mass of 4.
They're Heavy and slow(speed)In comparison to Beta particles and gamma rays
Usually Emitted from nucleus of radioactive nuclides during decay
Mass x height x gravity is the formula to calculate:
Answer:
Potential energy
Explanation:
[tex]p.e = mgh[/tex]
A sealed balloon filled with 5.00 liters of gas has a pressure of 1.49 atm. This balloon is taken under water where the pressure of the gas becomes 7.62
atm. What is the new volume of this gas? (Assume the temperature does not change.)
O 56.7L
0 0.978 L
0 1.02 L
O 2.27L
Answer:
0.978L
Explanation:
Using Boyle's law equation as follows;
P1V1 = P2V2
Where;
P1 = initial pressure (atm)
P2 = final pressure (atm)
V1 = initial volume (L)
V2 = final volume (L)
According to the provided information,
P1 = 1.49 atm
V1 = 5.00 liters
P2 = 7.62 atm
V2 = ?
Using P1V1 = P2V2
1.49 × 5 = 7.62 × V2
7.45 = 7.62V2
V2 = 7.45/7.62
V2 = 0.978L
Evolution can best be described as
A)
the change in size of body structures through use and disuse
B)
the formation of fossils
C)
a process of growth in an organism
D)
a process of change through time
WHAT IS EXOTHERMIC EXPLAIN
Explanation:
An exothermic reaction is a "reaction for which the overall standard enthalpy change ΔH⚬ is negative." Exothermic reactions usually release heat and entail the replacement of weak bonds with stronger ones.
hope it helps
stay safe healthy and happy..Answer:
Exothermic reactions are reactions or processes that release energy, usually in the form of heat or light. In an exothermic reaction, energy is released because the total energy of the products is less than the total energy of the reactants.Explanation:
I hope this helps u have a nice day ☘How did the first plants and animals arrive in Hawaii, before humans?
Si se hace reaccionar CH3CH3 (etano) con cloro, en presencia de luz ultravioleta, los productos obtenidos en este paso son
Answer:
La reacción de etano, CH₃CH₃ y cloro, Cl₂ en presencia de luz solar se conoce como reacción de halogenación.
Los radicales de cloro se forman cuando el cloro se expone a la luz solar a continuación;
Cl₂ → 2Cl *
Se forma un radical etano cuando el etano, C₂H₆ reacciona con un radical libre de cloro, Cl *, como sigue;
C₂H₆ + Cl → C₂H₅ * + HCl
Se forma un producto halogenado cuando un radical libre de etano reacciona con una molécula de cloro como sigue;
C₂H₅ * + Cl₂ → C₂H₅Cl + Cl *
Un producto halogenado puede reaccionar además con un radical libre para producir como sigue;
C₂H₅Cl + Cl * → C₂H₅Cl₂
Explanation:
What does it mean for something to be radioactive?
A. It has an emission spectrum.
B. It is in a stable condition.
C. It generates radio waves.
D. Its nuclei can split apart.
Answer:
D
Explanation:
Radioactivity means
the emission of ionizing radiation or particles caused by the spontaneous disintegration of atomic nuclei
hope this helps please like and mark as brainliest
What important points do you need to remember about combustion?
Explanation:
A substance burning in the presence of oxygen and leads to the formation of heat and light is called combustion.
Some important points about combustion are as follows:
Fuel should be present for burning.Air should be present for the supply of oxygen.There should be heat (or ignition temperature) to initiate the chemical reaction.1. Which of the following combinations correctly represents the process of
photosynthesis?
a) Carbon Dioxide + Water + solar energy - Glucose + Oxygen
b) Carbon Dioxide + Water - Glucose + Oxygen + solar energy
c) Glucose + Oxygen Carbon Dioxide + Water + energy
d) Glucose + Oxygen + energy +
Carbon Dioxide + Water
Answer:
A
Explanation:
Answer:
I think It should be option A. It would have been B but, solar energy is not giving out, it's taken in
Which substance would you expect to dissolve most rapidly in 100 mL water?
A
0.4 g granulated sugar
B
0.2 g powdered sugar
C
0.4 g powdered sugar
D
0.2 g sugar cube
Answer:
b because it is just 0.2 g and powdered sugar has more contact surface than granulated sugar or sugar cube
The solubility can be given as the amount of solute that can be dissolved in the 100 ml of the solution. The most rapidly dissolved sugar in water is 0.2 gram powdered sugar.
What is a contact surface?The contact surface can be given as the area of the compound that is in direct contact with the solution.
The solubility of the compound is found more in the solute with increased surface area.
The surface area of powdered sugar will be maximum, as more granules of the sugar will be in contact with the water than the cube or the granulated sugar.
Thus, the most rapid dissolution in water is found with 0.2 grams of powdered sugar. Thus, option B is correct.
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How is an endothermic reaction identified?
A. It has a large heat capacity.
B. It gives off heat as a product.
C. It requires heat as a reactant.
O D. It results in a phase change.
Answer:
Endothermic is identified if the process requires heat as a reactant, since endothermic means "intake of heat", so it has to take in some type of heat.
Which equation represents positron decay?
Answer: 4
Explanation:
I found it online
Reaction of hypochlorous acid and ammonia is product-favored system at equilibrium. Answer A: Reaction of hypochlorous acid and ammonia is product-favored system at equilibrium. A Reaction of hypochlorous acid and ammonia is reactant-favored system at equilibrium. Answer B: Reaction of hypochlorous acid and ammonia is reactant-favored system at equilibrium. B Reaction of hypochlorous acid and ammonia yields pH 7.00. Answer C: Reaction of hypochlorous acid and ammonia yields pH 7.00. C No reaction occurs between hypochlorous acid and ammonia. Answer D: No reaction occurs between hypochlorous acid and ammonia. D Further data are needed to draw a conclusion about a prospective reaction.
Answer:
A. True
B. False
Explanation:
Reaction between hypochlorous acid and ammonia does not yields a Ph value of 7.00 , this value is defined to water and no other reaction can yield exactly this Ph value. The acid reaction will give a Ph value below 7 while a base reaction will give Ph value of above 7.
Where does photosynthesis start?
Answer:
Have a nice day :)
Explanation:
the chloroplast
Photosynthesis occurs in the chloroplast, an organelle specific to plant cells. The light reactions of photosynthesis occur in the thylakoid membranes of the chloroplast. Electron carrier molecules are arranged in electron transport chains that produce ATP and NADPH, which temporarily store chemical energy.
Use the information from the diagram to calculate the enthalpy of combustion for methane. (HELP ASAPPP!!)
A)
+752 kJ
B)
–921 kJ
C)
–604 kJ
D)
+604 kJ
Answer:
where is the diagram sisters
This mathematical model describes the changes that occur in a sample of water as its temperature increases. Based on this model, how do you expect the motion of the molecules in ice to compare with the motion of molecules in water vapor?
A. I expect the molecules in ice to move more quickly than the molecules in water vapor.
B. This model does not provide enough data to answer the question.
C. I expect the motion to be very similar.
D. I expect the molecules n water vapor to move more quickly than the molecules in ice.
Answer:
D
Explanation:
the motion of particles can move more quickly due to weak force of attraction. water vapour is a gas hence the answer
4. A shepherd is increasing his heard from 300 goats to 600 goats. Currently, the land is sufficient to feed 300 goats; what could be the result?
Answer: 300 goats want get food
Explanation:
What is the equilibrium expression for the reaction below?
C(s) + O2(9)
2009)
[0][c]
O A.
[CO]
O B.
1
C с
OC.
[co]
[0][c]
CO2]
D.
Answer:
C
Explanation:
because it is product over reactants. hope this helps :)
The equilibrium expression for the reaction C(s) +[tex]O_{2}[/tex](g) ⇄ [tex]CO_{2}[/tex] (g) will be
[[tex]CO_{2}[/tex] ] / [ [tex]O_{2}[/tex] ].
What is equilibrium?Chemical equilibrium is a state where no net change in the quantities of reactants as well as products takes place during a reversible chemical reaction.
The given reaction is C(s) +[tex]O_{2}[/tex](g) ⇄ [tex]CO_{2}[/tex] (g) .
It is known that solid phase is not considered in equilibrium.
Hence, equilibrium expression = [[tex]CO_{2}[/tex] ] / [ [tex]O_{2}[/tex] ].
Therefore, the correct answer will be option (D).
To know more about equilibrium.
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What is the molarity of a 750 milliliters solution containing 54.0 grams of KBr (help me please)
Answer: The molarity of KBr solution is 0.605 M
Explanation:
Molarity is defined as the amount of solute expressed in the number of moles present per liter of solution. The units of molarity are mol/L.
The formula used to calculate molarity:
[tex]\text{Molarity of solution}=\frac{\text{Given mass of solute}\times 1000}{\text{Molar mass of solute}\times \text{Volume of solution (mL)}}[/tex] .....(1)
Given values:
Given mass of KBr = 54.0 g
Molar mass of KBr = 119 g/mol
Volume of the solution = 750 mL
Putting values in equation 1, we get:
[tex]\text{Molarity of solution}=\frac{54.0\times 1000}{119\times 750}\\\\\text{Molarity of solution}=0.605M[/tex]
Hence, the molarity of KBr solution is 0.605 M
Bacterial pathogens are grown in devices using a __________ developed to optimize the yield of the antigen while maintaining it's integrity.
Answer:
growth medium
Explanation:
The pathogenic bacteria are the bacteria which causes diseases. They may include fungi, worms, protozoa, viruses, bacteria, etc.
The bacterial pathogens are made to grow with the help of a growth medium which is developed to optimize the antigen's yield and also it maintains the integrity of the pathogenic bacteria.
What is the chemical formula of calcium chloride?
A.
CaCl
B.
Ca2Cl2
C.
Ca2Cl
D.
CaCl2
Answer:
D
Explanation:
calicium exchange valency of 2 with 1 valency of chlorine
What is the frequency of a photon with an energy of 3.26 x 10-19 J?
A. 2.03 x 1014 Hz
B. 4.92 x 1014 Hz
c. 6.10 * 1014 Hz
ОС
D. 5.69 x 1014 Hz
Answer:
B.
[tex]from \: eisteins \: energy \: relation : \\ E = hf \\ h \: is \: plancks \: constant\\ 3.26 \times {10}^{ - 19} = 6.63 \times {10}^{ - 34 } \times f \\ f = \frac{3.26 \times {10}^{ - 19} }{6.63 \times {10}^{ - 34} } \\ f = 4.92 \times {10}^{14} \: Hz[/tex]
