Answer:
wavelength
Explanation:
Which is TRUE about the structure of the atom? Select all that apply.
a
the densest part of the atom is the nucleus of the atom
b
the outermost part of the atom is where electrons are found
c
the nucleus of the atom is where protons and neutrons are found.
d
the outer part of the atom is called the antinucleus.
e
the nucleus of the atom has a diameter of about 10-10 m.
Why are most plants green out of all the colors?
Answer: Different forms of chlorophyll
Explanation:
Depending on the significance the of the chlorophyll it’s function is to absorb light, which excites electrons in the chlorophyll.
Answer:
Plant cells have an organelle called chloroplast in them. Chloroplast contains a green pigment called chlorophyll which gives plants it's green color.
Chlorophyll is important in plants as it helps the plant in producing food with the process of photosynthesis.
8. A saturated solution of Ag Croq has a silver-ion concentration of 1.3 x 10-4M. Which is the Ksp of Ag CrO 4?
O 1.3 x 10-4
O 3.9 x 10-12
O 6.5 x 10-5
O 1.1 x 10-12
Answer: The [tex]K_{sp}[/tex] of [tex]AgCrO_{4}[/tex] is [tex]1.1 \times 10^{-12}[/tex].
Explanation:
Given: [tex][Ag^{+}] = 1.3 \times 10^{-4} M[/tex]
The reaction equation will be written as follows.
[tex]Ag_{2}CrO_{4} \rightleftharpoons 2Ag^{+} + CrO^{2-}_{4}[/tex]
This shows that the concentration of [tex]CrO^{2-}_{4}[/tex] is half the concentration of [tex]Ag^{+}[/tex] ion. So,
[tex][CrO^{2-}_{4}] = \frac{1.3 \times 10^{-4}}{2}\\= 0.65 \times 10^{-4} M[/tex]
The expression for [tex]K_{sp}[/tex] of this reaction is as follows.
[tex]K_{sp} = [Ag^{+}]^{2}[CrO^{2-}_{4}][/tex]
Substitute values into the above expression as follows.
[tex]K_{sp} = [Ag^{+}]^{2}[CrO^{2-}_{4}]\\= (1.3 \times 10^{-4})^{2} \times 0.65 \times 10^{-4}\\= 1.1 \times 10^{-12}[/tex]
Thus, we can conclude that the [tex]K_{sp}[/tex] of [tex]AgCrO_{4}[/tex] is [tex]1.1 \times 10^{-12}[/tex].
According to kinetic-molecular theory, which of the following would not be considered an ideal gas? Check all that apply.
a gas at very high temperatures, when gas particles are moving very quickly
a gas at very low volumes, when gas particles are very close together
a gas at very low temperatures, when gas particles have very little kinetic energy
a gas at very low pressures, when gas particles are very far apart
a gas with highly polar molecules that have very strong intermolecular forces
Answer:
a gas at very low temperatures, when gas particles have very little kinetic energy
Explanation:
Answer:
B, C, and E!
Explanation:
got it correct on edge! :)
a beam balance is called a first class lever why?
Answer:
A beam balance is an example of a first class lever.
Explanation:
A beam balance is an example of a first class lever. In a first class lever, the fulcrum is between the effort (force) and the load. The effort (force) moves over a large distance to move the load a smaller distance.
Other examples of first class lever are pliers, scissors, a crow bar, a claw hammer, a see-saw and a weighing balance etc.
Which of the following is a base? (3 points)
AgO
Ca(OH)2
HF
NaCl
Answer:
Ca(OH)2 is base
is answer of this question
hope this will help you more
Answer:
Ca(OH)2
Explanation:
Got it right on the test
Which statement about biogeochemical cycles is true?
O A. Plants are a part of the nitrogen and carbon cycles, but not the
water cycle.
O B. Plants are a part of the nitrogen, carbon, and water cycles.
O c. Plants are a part of the water and carbon cycles, but not the
nitrogen cycle.
D. Plants are a part
carbon cycle.
the water and nitrogen cycles, but not the
Answer: The answer is D:
Answer:
The answer is Option D
Stae the change in oxidation state of iron during the reactiong of iron extraction
Answer:
3
Explanation:
The reaction for the extraction of Iron is :-
2Fe2O3(s) + 3C(s) → 4Fe(l) + 3CO2(g)
O.S. of Fe in Fe2O3 is 3 and O.S. of Fe(l) is 0change in oxidation state (O.S.) = higher O.S - lower O.S
= 3 - 0
= 3
help me please give two example in which physical change take place please help me
Answer:
Boiling, melting
Explanation:
Physical changes affect the form of a chemical substance.
an organic compound on analysis yielded 2.04g carbon, 0.34g hydrogen, 2.73g oxygen. calculate the empirical formula
Answer:
CH2O
Explanation:
According to this question:
C = 2.04g
H = 0.34g
O = 2.73g
First, we divide the mass value of each element by its atomic mass to convert to moles.
C = 2.04g ÷ 12 = 0.17mol
H = 0.34g ÷ 1 = 0.34mol
O = 2.73g ÷ 16 = 0.17mol
Next, we divide by the smallest mole value (0.17):
C = 0.17mol = 0.17 = 1
H = 0.34mol ÷ 0.17 = 2
O = 0.17mol ÷ 0.17 = 1
The whole number ratio of C,H,O is 1:2:1, hence, the empirical formula is CH2O.
A balloon, inflated in an air-conditioned room at 27.0°C, has a volume
of 4.50.L. It is heated to a temperature of 57.0°C. What is the new
volume of the balloon if the pressure remains constant?
Answer:
4.95L
Explanation:
Using Charle's law equation;
V1/T1 = V2/T2
Where;
V1 = initial volume (L)
V2 = final volume (L)
T1 = initial temperature (K)
T2 = final temperature (K)
According to the question, the following information was given:
V1 = 4.50L
V2 = ?
T1 = 27°C = 27 + 273 = 300K
T2 = 57°C = 57 + 273 = 330K
Using V1/T1 = V2/T2
4.50/300 = V2/330
Cross multiply
300 × V2 = 4.5 × 330
300V2 = 1485
V2 = 1485 ÷ 300
V2 = 4.95L
Which statement is not true about the periodic table?
A. Elements in the same family have the same number of protons.
B. An element of the table is represented by a box with a symbol in it.
C. Elements in the same period of the periodic table have the same
number of electron shells.
D. It is organized by atomic number.
Elements in the same family have the same number of protons. This statement is not true about the periodic table. Therefore, option A is correct.
What is periodic table ?The chemical elements are arranged in rows and columns in the periodic table, sometimes referred to as the periodic table of the elements. It is frequently used in physics, chemistry, and other sciences and is frequently regarded as a symbol of chemistry.
The table can be used by scientists to anticipate chemical reactions, study trends in the periodic properties of certain elements, and speculate on the properties of yet-to-be-discovered elements. The elements are arranged in the contemporary periodic table according to their atomic numbers and periodic characteristics.
The periodic table has changed to represent more than 150 years of chemical and physics research and development.
Thus, option A is correct.
To learn more about the periodic table, follow the link;
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What two elements were named after the United States?
What pollutants can contribute to acid precipitation and how are these pollutants generated?
Answer:
I don't know I don't know about question but I can try to find it
Explanation:
I don't know about question but I can try to find it
Which general equation shows a double-displacement reaction?
O A. AB + CD + AC + BD
O B. AB → A+B
O C. AB + CD → AD + CB
O D. A+B → AB
Answer:
O A. AB + CD + AC + BD
explanation:
Explanation:
A.ab+cd+ac+bd is your answer
El fluoruro de hidrógeno HF que se utiliza en
la obtención de los freones (los cuales
destruyen la capa de ozono de la
estratosfera), se prepara mediante la
siguiente reacción: CaF2 + H2SO4
CaSO4 + 2HF Si se hacen reaccionar 50gr
de CaF2 con 100 gr de H2SO4 (masas
atómicas Ca=40,F=19, H=1, S=32, O=16)
Answer:
25.6g de HF son producidos
Explanation:
...¿Cuánto HF es producido?
Para resolver este problema debemos convertir la masa de cada reactivo a moles usando su masa molar. Como la reacción es 1:1, el reactivo con menor número de moles es el reactivo limitante. Con las moles del reactivo limitante podemos obtener las moles de HF y su masa así:
Moles CaF2:
Masa molar:
1Ca = 40g/mol
2F = 19*2 = 38g/mol
40+38 = 78g/mol
50g CaF2 * (1mol/78g) = 0.641 moles CaF2
Moles H2SO4:
Masa molar:
2H = 2g/mol
1S = 32g/mol
4O = 64g/mol
98g/mol
100g H2SO4 * (1mol / 98g) = 1.02 moles H2SO4
Como las moles de CaF2 < Moles H2SO4: CaF2 es reactivo limitante.
Moles HF usando la reacción:
0.641 moles CaF2 * (2mol HF / 1mol CaF2) = 1.282 moles HF
Masa HF:
Masa molar:
1g/mol + 19g/mol = 20g/mol
1.282 moles HF * (20g/mol) =
25.6g de HF son producidosThe reaction below shows how the potential energy changes during a phase
change. What does the red arrow show?
Potential Energy
Reaction Progress
A. The change in enthalpy is positive, and the reaction is
endothermic.
B. The change in enthalpy is negative, and the reaction is exothermic.
C. The activation energy is negative, and the reaction is exothermic.
D. The activation energy is positive, and the reaction is endothermic.
Answer:
the red arrow shows that the change in enthalpy is positive
From the energy diagram, it is clear that, the enthalpy of the reaction is positive and it is an endothermic reaction.
What is an endothermic reaction ?An endothermic reaction is a chemical reaction that absorbs heat from its surroundings, resulting in a decrease in temperature of the surroundings. In other words, energy is taken in by the reaction from the environment.
During an endothermic reaction, the reactants absorb energy in the form of heat, light, or electricity to break the bonds between their atoms and form new bonds to create products.
The amount of energy absorbed by the reactants is greater than the energy released by the products. This energy difference is usually expressed as the enthalpy change (∆H) of the reaction, which is positive for endothermic reactions.
Here, the energy of products is higher than that of reactants and hence option A is correct.
Find more on endothermic reaction:
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Select the correct answer.
Which missing item would complete this beta decay reaction?
ОА. 0,-1В
OB. 0,0y
OC. 4,2He
OD. 0,1n
Reset
Answer:
Option A. ⁰₋₁β
Explanation:
Let the unknown be ʸₓA
Thus, the equation given becomes:
⁹⁸₄₃Tc —> ⁹⁸₄₄Ru + ʸₓA
Next, we shall determine the value of x, y and A in order to obtain the answer to the question. This can be obtained as follow:
43 = 44 + x
Collect like terms
43 – 44 =
–1 = x
x = –1
98 = 98 + y
Collect like terms
98 – 98 = y
0 = y
y = 0
ʸₓA => ⁰₋₁A => ⁰₋₁β
Thus, the complete equation is
⁹⁸₄₃Tc —> ⁹⁸₄₄Ru + ⁰₋₁β
The missing item is ⁰₋₁β
Answer the two questions for 15pts
Answer:
For 1: 6.68 g of nitrogen dioxide will contain [tex]8.73\times 10^{22}[/tex] number of molecules
For 2: The given amount of nitrogen dioxide molecules has a mass of 41.31 g.
Explanation:
According to the mole concept:
1 mole of a compound contains [tex]6.022\times 10^{23}[/tex] number of molecules
The number of moles is defined as the ratio of the mass of a substance to its molar mass. The equation used is:
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex] ......(1)
For 1:We are given:
Mass of nitrogen dioxide = 6.68 g
Molar mass of nitrogen dioxide = 46 g/mol
Putting values in equation 1, we get:
[tex]\text{Moles of nitrogen dioxide}=\frac{6.68g}{46g/mol}=0.145mol[/tex]
Using above concept:
If 1 mole of a compound contains [tex]6.022\times 10^{23}[/tex] number of molecules
So, 0.145 moles of nitrogen dioxide will contain = [tex](0.145\times 6.022\times 10^{23})=8.73\times 10^{22}[/tex] number of molecules
Hence, 6.68 g of nitrogen dioxide will contain [tex]8.73\times 10^{22}[/tex] number of molecules
For 2:We are given:
Molecules of nitrogen dioxide = [tex]5.41\times 10^{22}[/tex] molecules
Using the above concept:
If [tex]6.022\times 10^{23}[/tex] number of molecules are present in 1 mole of a compound
So, [tex]5.41\times 10^{22}[/tex] number of molecules will be present in = [tex]\frac{1mol}{6.022\times 10^{23}}\times 5.41\times 10^{22}=0.898[/tex] moles of nitrogen dioxide
We know, molar mass of nitrogen dioxide = 46 g/mol
Using equation 1:
[tex]0.898mol=\frac{\text{Mass of nitrogen dioxide}}{46g/mol}\\\\\text{Mass of nitrogen dioxide}=0.898mol\times 46g/mol=41.31g[/tex]
Hence, the given amount of nitrogen dioxide molecules has a mass of 41.31 g.
What is the balanced form of the chemical equation shown below?
Ca(OH)2(aq) + Na2CO3(aq) CaCO3(s) + NaOH(aq)
A. Ca(OH)2(aq) + Na2CO3(aq) CaCO3(s) + 2NaOH(aq)
B. 2Ca(OH)2(aq) + Na2CO3(aq) 2CaCO3(s) + 2NaOH(aq)
C. CaOH(aq) + Na2CO3(aq) CaCO3(s) + Na2OH(aq)
D. Ca(OH)2(aq) + Na2CO3(aq) CaCO3(s) + NaOH(aq)
Answer:
B
Explanation:
. 2Ca(OH)2(aq) + Na2CO3(aq) 2CaCO3(s) + 2NaOH(aq)
A. Ca(OH)2(aq) + Na2CO3(aq) CaCO3(s) + 2NaOH(aq)
Match the reaction to the type that best describes it.
2HCl → H2 + Cl2
?
Combination
NaF + KBr →
NaBr + KE
?
Decomposition
Mg + MnCl2 →
-Mn + MgCl2
?
Single replacement
2Na + 02 →
Na2O2
?
Double replacement
Answer:
2HCl → H2 + Cl2 = decomposition
NaF + KBr → NaBr + KF = double replacement
Mg + MnCl2 → Mn + MgCl2 = single replacement
2Na + 02 → Na2O2 = combination
Explanation:
A chemical reaction involves the conversion of one or more substances called REACTANTS into other substances called PRODUCTS. There are different types of reactions depending on how it occurs, they include:
- Combination or synthesis reaction is a type of reaction in which two or more elements combine to form a single product. Example is:
2Na + 02 → Na2O2
- Single replacement is a type of reaction where one element is replaced by another in a compound or molecule. Example below shows that Manganese (Mn) is replaced by magnesium (Mg):
Mg + MnCl2 → Mn + MgCl2
- Double replacement is a type of reaction where two elements are replaced by other elements at a time. Example is:
NaF + KBr → NaBr + KF
- Decomposition is a type of reaction in which one molecule or compound is broken down into two or more products. Example is:
2HCl → H2 + Cl2
State one human activity that increase the amount of carbon dioxide in the atmosphere today.
Answer:
Burning of fossil fuels
Explanation:
Human activities that increase the amount of carbon dioxide in the atmosphere are;
1) Burning of fossil fuels in industrial and internal combustion engines
2) Depletion of the available forest cover, due to the consumption of wood as a raw material
3) Farming expansion that lead to clearing of forests for farming
4) Industrial activities such as the production of cement
5) Deforestation to provide land for development including buildings and infrastructure.
Which statement is the best description of a chemical bond
Answer:
What are your given options? I can't answer unless I know those :)
Explanation:
El suero fisiológico tiene una concentración de 8,78 gr/lt. Calcula la masa de NaCl que ingresa en el organismo de un paciente al que se le administra suero durante 4 hs con una velocidad de goteo de una gota por segundo (Volumen gota: 0,05 ml)
Un paciente que recibe suero fisiológico a una velocidad de infusión de 1 gota = 0,05 ml por segundo recibirá en 5 horas 790 grs de NaCl, tomando en cuenta que la solución acuosa de suero fisiológico contiene 0,878 grs/mL de NaCl.
Explicación
Los datos que se tienen son:
Concentración de NaCl 0,878 grs/mlVolumen de la gota: 0,05 ml/gotaVelocidad de infusión 1 gota/ seg = 60 gotas/ min = 3 ml/minTiempo de infusión = 5 horas = 300 minutosYa establecidas las respectivas conversiones se trata de determinar qué volumen de suero fisiológivo se ha infundido al paciente en 5 horas
Si se infunden 3 ml cada minuto, ¿Cuánto se habrá infundido en 300 minutos?
3 ml ______________ 1 min
X ________________ 300 min
X = (300 min x 3 ml) / 1 min
X = 900 ml
Como en 5 horas el paciente ha recibido 900 ml de suero, se determina la cantidad de NaCl que se encuentra en ese volumen de líquido
0,878 grs __________ 1 ml
X ________________ 900 ml
X = (900 ml x 0,878 grs) / 1 ml
X = 790 grs de NaCl
Which of the following statements about the nucleus is false?
A. Contains nearly all of the mass of the atom.
B. Able to be lost or gained in chemical reactions.
C. None of these
D. Made up of protons and neutrons
Answer:
B. Able to be lost or gained in chemical reactions.
Answer:
B
Explanation:
a chemical reaction would only move the nucleas
Which has more mass, 2 kg of steel or 5 kg of feather.
Answer:
5 kg of feather
Explanation:
WHAT IS PHOTOSYNTHESIS??
Answer:
the process by which green plants and some other organisms use sunlight to synthesize nutrients from carbon dioxide and water. Photosynthesis in plants generally involves the green pigment chlorophyll and generates oxygen as a by-product.
Answer:
the process by which green plants and some other organisms use sunlight to synthesize nutrients from carbon dioxide and water. Photosynthesis in plants generally involves the green pigment chlorophyll and generates oxygen as a by-product.
What mss of sulfamic acid is required to make 250cm3 of a 0.150mol/dm3 solution? please help
Answer:
sorry i dint understand can u ask it in a simpler way
Explanation:
(d) (i) How can the water molecules from the iceberg end up as water in the lake?
Explanation:
If the iceberg is near the lake and the water molecules melt, then the molecules will slide down. The iceberg could be melting for many reasons - it can be purposely destroyed, the sun could be melting it, or it might naturally fall in. So, this is the answer to your question. Hope it helps!
Give reasons: a) Cocoons are boiled in hot water. b) Camel wool considered a natural health product.
Answer:
•cocoons are boiled in hot water for obtaining silk fibres from cocoons.
•camel wool considered a natural health product because it has excellent thermal proities
