los metales se oxidan
Select the correct answer.
A sample taken from a layer of mica in a canyon has 2.10 grams of potassium-40. A test reveals it to be 2.6 billion years old. How much
potassium-40 was in the sample originally if the half-life of potassium-40 is 1.3 billion years?
O A.
4.20 g
O B.
8.40 g
O C.
12.6 g
• D.
16.8 g
O E.
25.2 g
Answer:
8.36 g
Explanation:
From;
0.693/t1/2 = 2.303/t log (No/N)
t1/2 = half life of potassium-40
t = age of the sample
No= initial amount of the sample
N= amount of the sample at time t
Substituting values;
0.693/1.3 × 10^9 = 2.303/2.6 × 10^9 log (No/2.10)
5.33 × 10^-10 = 8.86 × 10^-10 log (No/2.10)
5.33 × 10^-10/8.86 × 10^-10 = log (No/2.10)
0.6 = log (No/2.10)
Antilog (0.6) = (No/2.10)
No = 2.10 × Antilog (0.6)
No= 8.36 g
name any two mix metals with one use from each.
Answer:
bronze, copper
Explanation:
bronze is used to make medals and carve statues
copper is used to make wire and utensils
name the gas which is formed when coal is heated in the absense of air
Answer:
Coke
Explanation:
A solid fuel formed by heating coal in the absence of air is coke. Coke is black colored, tough porous substance. It is pure carbon.
SOMEONE HELP ASAP I NEED TO FIND AN ANSWER
Answer:
A) Q + XZ = X + QZ is a single displacement reaction.
B) Q + Z = QZ is a synthesis reaction
C) QT = Q + T is a decomposition reaction
D) QT + XZ = QZ + XT is double replacement reaction.
Explanation:
A) Q + XZ = X + QZ
This is a single displacement reaction because it is one in which one element is substituted for another one in a compound. In this case X is substituted for Q.
B) Q + Z = QZ
This is a synthesis reaction because Q and z combine to form a single product QZ.
C) QT = Q + T
This is a decomposition reaction because the compound QT breaks down to form 2 simpler substances Q and T.
D) QT + XZ = QZ + XT
Thus is a double replacement reaction because QT and XZ have exchanged cations to form new compounds QZ and XT
The osmotic pressure of a solution formed by dissolving 0.231 g of the protein in 150 mL of water at 298 K is found to be 2.054 torr.
Answer:
13924g/mol is the molar mass of the protein
Explanation:
What is the molar mass of the protein.
The osmotic pressure of a solution, π, is defined as:
π = c*R*T
Where π is osmotic pressure = 2.054torr* (1atm/760torr) = 2.70x10⁻³atm
c is molar concentration of the protein,
R is gas constant = 0.082atmL/molK
And T is absolute temperature = 298K
Solving the molar concentration:
c = π / RT
c = 2.70x10⁻³atm / 0.082atmL/molK*298K
c = 1.106x10⁻⁴ moles protein / L
The moles of protein in 150mL = 0.150L:
0150L * (1.106x10⁻⁴ moles protein / L) = 1.659x10⁻⁵ moles protein
The molar mass is the ratio of mass and moles:
0.231g / 1.659x10⁻⁵ moles protein =
13924g/mol is the molar mass of the proteinWhich reaction occurs at the cathode of a galvanic cell that has an aluminum electrode in an electrolyte with aluminum ions and copper electrode in an electrolyte with copper ions ? The reduction potential for the reduction of Cu^ 2+ = 0.34 The reduction potential for the reduction of AP^ 3+ =-1.68V.
Answer:
[tex]{ \bf{Cu {}^{2 + } + 2e \: → \: Cu }}[/tex]
The reaction that occurs at the cathode of a given galvanic cell is:
Cu²⁺ + 2e⁻ → Cu
What is Galvanic Cell?A galvanic cell can be defined as an electrochemical cell that converts the chemical energy of spontaneous redox reactions into electrical energy. The galvanic cell makes use of chemical reactions to generate electrical energy.
A galvanic cell consists of two half-cells and a salt bridge. Each half-cell further contains an electrode dipped into an electrolyte. When both electrodes are dipped in the same electrolyte, then there is no need for a salt bridge.
At the anode, an oxidation reaction occurs at this electrode. At the cathode, reduction occurs at this electrode. The anode has a negative potential with respect to the solution while the cathode has a positive potential with respect to the solution.
As in the question, the reduction of Cu²⁺ has a positive reduction potential. Therefore, the reduction of the copper will occur at the cathode.
Learn more about Galvanic cell, here:
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According to the kinetic-molecular theory, the average kinetic energy of gas particles depends on which factor?
Answer:
Temperature.
Explanation:
Kinetic molecular theory of gases states that gas particles exhibit a perfectly elastic collision and are constantly in motion.
According to the kinetic-molecular theory, the average kinetic energy of gas particles depends on temperature.
This ultimately implies that, the average kinetic energy of gas particles is directly proportional to the absolute temperature of an ideal gas. Thus, an increase in the average kinetic energy of gas particles would cause an increase in the absolute temperature of an ideal gas.
Temperature can be defined as a measure of the degree of coldness or hotness of a physical object. It is measured with a thermometer and its units are Celsius (°C), Kelvin (K) and Fahrenheit (°F).
What would happen to the entropy in the reaction 203(9) ► 302(9)?
A. It is impossible to tell.
B. It stays the same.
C. It decreases.
D. It increases.
bez number of particles in reaction increases so randomness or entropy increase.
as entropy is the degree of randomness of particles in a system
Use the average acceleration obtained in Activity 1 to determine how far the ball should drop at 0.3 second, 0.5 second, and 0.7 second. Using the simplified formula y = 1/2 at2 (because y0 = 0 and v0 = 0), calculate y to one decimal place.
Answer:
0.3 sec : -0.4 m
0.5 sec: -1.2 m
0.7 sec: -2.3 m
Explanation:
0.3 sec: 1/2(-9.3 m/s^2)(0.3 s)^2 = -0.4 m
0.5 sec: 1/2(-9.3 m/s^2)(0.5 s)^2 = -1.2 m
0.7 sec: 1/2(-9.3 m/s^2)(0.7 s)^2 = -2.3 m
Help please I’ll give you brainless
Answer:
Step 9
Explanation:
The reason i selected step 9, is if you take a look at the picture hes setting up a funnel,With filter paper and if you take a look at number ''9'' questions it says set up a funnel, filter paper and filter flask which is shown in the picture on top that's how i got my answer
Hi Everyone ✌
hope u all r doin well
Pls Answer
What happens when dilute sulphuric acid is poured on a copper plate ?
Answer:
No observable change.
Explanation:
Copper renders dilute sulphuric acid passive, no reaction.
H2SO4+Cu-->CuSO4+H2
Explanation:
THIS IS THE CORRECT ANSWER
Se trata 50 g de aluminio que posee 10% de impurezas con suficiente cantidad de ácido sulfúrico ¿qué peso de sulfato de aluminio se obtiene si el porcentaje de rendimiento fue de 70%? P.A. (uma): Al: 27, S = 32, O = 16
Respuesta:
199.5 g
Explicación:
Paso 1: Escribir la reacción balanceada
2 Al + 3 H₂SO₄ ⇒ Al₂(SO₄)₃ + 3 H₂
Paso 2: Calcular la masa pura de 50 g de Al
Aluminio tiene 10% de impurezas, es decir, 10% de 50 g = 5 g. Luego, tiene 50 g - 5 g = 45 g de Al puro.
Paso 3: Calcular la masa teórica de Al₂(SO₄)₃ obtenida a partir de 45 g de Al
La relación de masas de Al₂(SO₄)₃ a Al es 342:54.
45 g Al × 342 g Al₂(SO₄)₃/54 g Al = 285 g Al₂(SO₄)₃
Paso 4: Calcular la masa real de Al₂(SO₄)₃ obtenida
El rendimiento de la reacción es de 70%.
285 g × 70% = 199.5 g
What is pH?
O A. A measurement indicating how acidic a solution is
B. A concentration of total ions dissolved in solution
C. A level of dissolved gases that are in solution
O D. A component of solutions that makes them acidic
Answer:
Awnser is A
Explanation:
Answer:
Hello There!!
Explanation:
The answer is↬O A. A measurement indicating how acidic a solution is.
hope this helps,have a great day!!
~Pinky~
Explain and describe how the photoelectric effect occurs on an atomic level in terms of protons, neutrons, and electrons
ANSWER:
Explaining the experiments on the photoelectric effect. How these experiments led to the idea if light behaving as a particle of energy called a photon.
what is the change of state from gas to liquid
Vapourization and condensation. the actual 1 shud be vapourization.
The ksp of StS04 is 3.2x10-7 What is the equilibrium concentration of sulfate lon a 1.0-L solution of strontium sulfate to which 0.10 mol of Sr(CH3CO2)2 has been added?
Answer:ehwusvudhwdvwxkwvbxbwxbxiwhxjvwxjvxwjxvjxvwxiwvxiwzgiwxvwjsbwis
HOPE IT HELPS IF YOU LIKE MY ANSWER THEN MARK ME AS BRAINLIEST ;-);-)
A gardener decides to use only part of their garden in the spring. What will most likely happen first in the unused part of the garden?
Answer:
Growth of weeds and grasses
Explanation:
The part of the garden, probably left to rest by the Gardner, would start experiencing a legion of invasive plants. Giant weeds and grasses could be seen, and brambles and tree seedlings could also sneak in.
Some Gardeners would recommend the use of herbicides to restore order to an abandoned garden even though certain scientists are of the opinion that chemicals may not offer a sound solution to the problem.
Match each word to its correct meaning. 1. carbon sequestration carbon dioxide, water vapor, methane, nitrogen oxides, and some CFCs that absorb heat and keep it in the earth's atmosphere 2. greenhouse effect technology used to capture the carbon released from smokestacks and store it in some part of the environment to keep it out of the atmosphere 3. greenhouse gas a term used to describe the role that greenhouse gases play in keeping the earth warm
Answer:
1. Greenhouse gas.
2. Carbon sequestration.
3. Greenhouse effect.
Explanation:
Greenhouse gases can be defined as gases that trap heat within the Earth's atmosphere. Thus, an increase in global temperature is largely caused due to an increase in the amount of greenhouse gases in Earth's atmosphere.
Some examples of greenhouse gases present in the atmosphere are methane, water vapor, carbon dioxide etc.
Matching the descriptions with their term respectively, we have;
1. Greenhouse gas: carbon dioxide, water vapor, methane, nitrogen oxides, and some CFCs that absorb heat and keep it in the earth's atmosphere
2. Carbon sequestration: it's a technology used to capture the carbon released from smokestacks and store it in some part of the environment to keep it out of the atmosphere. Thus, it's a process that is typically used for capturing and the long-term storage of atmospheric carbon dioxide in soil, ocean, plants and geologic formation, so as to reduce global warming or climate change.
3. Greenhouse effect: it's a term used to describe the negative role that greenhouse gases such as methane, water vapor, carbon dioxide etc., play in keeping the earth warm.
Joelle is a manager at a construction company, and she is interested in the chemistry behind the materials they use. She has begun studying the materials used to fill walls. She knows that to keep the temperature inside a room steady the material must be a thermal insulator, and she predicts that materials should not be acidic or else they would dissolve too easily in water. Which of these is a molecular ingredient that could be used in a wall-filling material ?
Answer: C6H6
Explanation:
The molecular formula C₆H₆ represents Benzene. Benzene is colorless, flammable, and has a sweet and gasoline-like odor. It's a toxic chemical, and can cause cancer.
Benzene is a hydrocarbon and used for the manufacturing of products such as plastic, detergents, glues, dyes, and rubber. It can also be used in making wall-filling material.
Answer: C6H6
Explanation:
The molecular formula C₆H₆ represents Benzene. Benzene is colorless, flammable, and has a sweet and gasoline-like odor. It's a toxic chemical, and can cause cancer.
Benzene is a hydrocarbon and used for the manufacturing of products such as plastic, detergents, glues, dyes, and rubber. It can also be used in making wall-filling material.
Antara berikut ciri manakah bear tentang cuka?
A. Berasa pahit.
B. Berasa tawar.
C. Nilai pH kurang dari 7
D. Nilai pH ialah 7
Answer:
c. nilai pH kurang dari 7
Explanation:
cuka adalah acid
nilai pH bagi acid adalah
antara 1 hingga 6
If no loss or gain of electrons occur by mixing of two atoms, we say that they may be attached to each
other due to
A proton attraction
B neutron attraction
C sharing of electrons
D opposite charges
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Answer:
The correct option is option C
Explanation:
Loss or gain of electron(s) occurs in a type of attraction known as electrovalent or ionic attraction. In this type, there is transfer (or loss) of electron(s) from a metal atom to become positively charged while a nonmetal accepts (or gains) this electron to become negatively charged.
When this does not happen, two metal atoms can become attached by sharing the same electrons through a form of attraction known as covalent bonding. Here, the two atoms share electrons (known as shared pair) together to achieve there octet configuration on the outermost shell.
You're a dentist and want your patients to have the cleanest smiles possible. You're not sure which toothpaste to recommend and decide to design an
experiment to determine which toothpaste gives the brightest and whitest smile.
1) What variables would you need to control in your
experiment?
2) Which variable would you change to determine which toothpaste is best?
3) What is the measurable outcome for this experiment?
d) What would the procedure be for your experiment? Please help me to answer this questions:(
Answer:
Why do you need good toothpaste?
Explanation:
Answer:
Do this yourself smh this isnt what the wesite is for
Explanation:
A solution of ammonia NH3(aq) is at equilibrium. How would the equilibrium
change if NH4+ were added to the solution?
Answer: The equilibrium will shift in the direction of [tex]NH_3[/tex]
Explanation:
The chemical equation for the aqueous solution of ammonia follows:
[tex]NH_3+H_2O\rightleftharpoons NH_4^++OH^-[/tex]
According to Le-chtelier's principle:
If there is any change in the variables of the reaction, then the equilibrium will shift in that direction of equilibrium to minimize the effect.
If we add more amount of [tex]NH_4^+[/tex] to the solution, more of the products will be present. But according to Le-chtelier's principle, to minimize this effect, the equilibrium will shift in the backward direction that in the direction of [tex]NH_3[/tex]
Hence, the equilibrium will shift in the direction of [tex]NH_3[/tex]
Which of the following increases the ratio?
Both β+ and β– decay
Only β– decay
Neither β+ nor β– decay
Only β+ decay
Answer:
Only β+ decay
Explanation:
In positron emission, a proton is converted into a neutron and a positron. An anti neutrino is a particle that serves the purpose of balancing the spins.
During positron emission, the mass number to the daughter nucleus is the same as that of the parent nucleus but the atomic number of the daughter nucleus is less than that of the parent nucleus by one unit.
Positron emission increases the neutron/proton ratio.
5. Which choice best represents the relationship between wavelength and frequency?
when frequency decreases, wavelength decreases
there is no relationship
when frequency increases, wavelength increases
O when frequency decreases, wavelength increases
Select the atoms that are likely to gain electrons to form anions:
A. Cesium (Cs)
B. Chlorine (CI)
c. Nitrogen (N)
D. Sulfur (S)
hurryyy asap make u the brainlyeist
Answer:
c
Explanation:
which is an example of the force of attraction between two obects that have mass?
Answer:
gravity
Explanation:
Gravity is an example of the force of attraction between two objects that have mass.
What is a reaction rate
Answer:
Explanation:
A reaction rate is the measure of the change in concentration of the disappearance of reactants or the change in concentration of the appearance of products per unit time
What type of nuclear decay is shown by the reaction below?
A. Alpha
B. Gamma
C. Beta
O D. Fission
Answer:
C. Beta
Explanation: