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 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
How much energy does a 930 nm wave of light have? (The speed of light in a vacuum is 3.00 x 108 m/s, and Planck's constant is 6.626 x 10-34 J·s.)
A. 4.68 x 10^18 J
B. 2.14 x 10^-19 J
C. 1.85 x 10^-31 J
D. 4.21 x 10^35 J
Answer:
B. 2.14 x 10^-19 J
Explanation:
The energy of a wave of light can be obtained using the equation:
E = h*c/λ
Where E is the energy in joules,
λ is wavelength = 930nm = 930x10⁻⁹m
h = Planck's constant = 6.626x10⁻³⁴Js
c = Speed of light = 3.00x10⁸m/s
Replacing:
E = 6.626x10⁻³⁴Js*3.00x10⁸m/s/930x10⁻⁹m
E = 2.14x10⁻¹⁹J
Right option is:
B. 2.14 x 10^-19 J
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
tolong saya jawab yahhh
(i) Liang - liang stoma lebih banyak di bahagian bawah daun berbanding di bahagian atas permukaan daun.
(ii) Struktur X berfungsi mangawal pembukaan dan penutupan liang stoma
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.
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 point A on the phase diagram called?
liquid
(374°C/218 atm)
A
solid
pressure (atm)
gas
temperature (°C)
OA.
the melting point
OB.
the boiling point
Ос.
the freezing point
OD
the critical point
OE.
the triple point
Answer:
D) the critical point
Explanation:
Point A is the critical point in phase diagram. This is the highest temperature and pressure at which a pure material can exist in vapor/liquid equilibrium. Pretty cool!
SOMONE HELP DUE IN 5 MINUTES
Answer:
Silicon
Explanation:
Nucleus
14 protons
Group 14
Number 14
+4, +2, or -4
Answer:
Explanation:
Name of the part of this atom labeled z is nucleus.
number of protons is 14 .
the given element is silicion and it lies in group 14.
the no of period that contains this element is 3.
charge formed on the ion formed from this atom is positive charge because it gives 4 electron to other element .
If the element gains the electron then it has negative charge where as when it loses it will have positive charge.
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~
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 particles are attracted as a result of the electrostatic force?
A. Protons and electrons
B. Any particles that have mass
C. Any particles that have like charges
D. Protons and neutrons
Answer:
A. Protons and electrons
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.
Boyle's Law Problems
Charles' Law Problems
Answer:
here are the answers babe. Feel free to ask for more
If one of the reactants in a reaction us Na2O, what is known about the products?
Ok here's the deal
the answer is A: The products will contain exactly 2 Na atoms and 1 O atom.
Explanation:
thank me later space-ex kids
PLZ HELP!!! QUESTIONS ARE BELOW!!! :D PLZ COMPLETELY ANSWER THE QUESTIONS WITH A GOOD ANSWER :)
Answer: sorry its lagging i hope this help fore 18.. =D
Explanation:
n,s is repeating the cycle of the inside
Answer/Explanation:
18, a,
I believe the n, and s represents North, South, or just the way the arrows are rotating repeatedly.
18, b,
The phenomenon re-occurring shows the alignment of magnetic dipoles with in a magnet, like inside. The arrows show a direction in the line with an external magnetic field in a way that it can produce its own magnetic fields that seem to travel from North to the South.
18, c,
Incorrect. Refrigerator magnets have multiple layers of magnification, they use opposite polarities to stay this way. If he puts the magnet sideways it may stick to the fridge
~ LadyBrain
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
What type of nuclear decay is shown by the reaction below?
A. Alpha
B. Gamma
C. Beta
O D. Fission
Answer:
C. Beta
Explanation:
los metales se oxidan
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.
How many electron containing orbitals are in an atom of tin ?
Answer:
10
Explanation:
how many electron-containing d orbitals are there in an atom of tin? name the element in the 4th period whose atoms have the same number of highest-energy-level elctrons as tin
10, germanium
Two or more than two atoms with different physical or chemical properties can not combine together to form an element. Therefore, the total number of orbitals containing electrons in an atom of tin are 10 orbitals.
What is element?Element generally consist of atoms or we can atoms combine to form element. Atoms of an element is always same, means all the properties of all atoms of one type of element is same.
The electronic configuration of tin is 1s² 2s² 2p⁶ 3s²3p⁶ 4s² 3d¹⁰ 4p⁶ 5s²4d¹⁰ 5p² or [Kr] 5s² 4d¹⁰ 5p². The total number of orbitals containing electrons in an atom of tin are 10 orbitals. tin an element that belongs to p block of periodic table.
Therefore, the total number of orbitals containing electrons in an atom of tin are 10 orbitals.
To know more about element, here:
https://brainly.com/question/8460633
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Una muestra de 2,5000 (g) de piedra caliza, se disuelve y se precipita el Calcio como oxalato de Calcio (CaC2O4), este precipitado se calcina transformándose en Carbonato de Calcio (CaCO3). El peso de este compuesto es de 1,2093 (g). Calcular el % de Calcio en la muestra
Answer:
[tex]\%Ca=19.378\%[/tex]
Explanation:
¡Hola!
En este caso, basado en la información dada, es posible conocer la masa de calcio en carbonato de calcio, que de hecho es la misma en la muestra, al utilizar el siguiente esquema de cálculo:
[tex]m_{Ca}=1,2093gCaCO_3*\frac{1molCaCO_3}{100.1gCaCO_3}*\frac{1molCa}{1molCaCO_3}*\frac{40.1gCa}{1molCa}\\\\m_{Ca}=0.48444gCa[/tex]
Finalmente, calculamos el porcentaje requerido como sigue:
[tex]\% Ca=\frac{0.48444g}{2.5000g} *100\%\\\\\%Ca=19.378\%[/tex]
¡Saludos!
The temperature of a sample of liquid water changes from 50°C to 30°C. Which statement best explains the change
that must happen at the molecular level?
The molecules move more quickly and their average kinetic energy increases
The molecules move more bowly and their average kinetic energy decreases
The molecules move more quickly and their average kinetic energy decreases
The molecules move more slowly and their average kinetic energy increases.
Answer:
The molecules move slower than the temp of 50°c and their average kinetic energy decreases.
Explanation:
kinetic energy cannot increase as temperature is reduced. molecules will still move with reduced motion.
HELP! HELP! Calculate the value of ΔS⁰ at 298 K.
Answer:
ΔS⁰ = -181.1J/molK
Explanation:
ΔS⁰ of a reaction is defined as the sum of the entropies of the reactants times its reaction coefficient minus the sum of the entropies of the products times its reaction coefficient. For the reaction in the problem:
ΔS⁰ = 2*S{NaCl(s)} - (2*S{Na(s)}+S{Cl2(g)})
ΔS⁰ = 2*72.1J/molK - (2*51.1J/molK + 223.1J/molK)
ΔS⁰ = -181.1J/molKAntara 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
1.1 Define the concept risky behaviour?
Answer:
Risky behavior or risk-taking behavior is defined according to Trimpop (1994) as “any consciously, or non-consciously controlled behavior with a perceived uncertainty about its outcome, and/or about its possible benefits, or costs for the physical, economic or psycho-social well-being of oneself or others.” In addition to this broad definition, there are other definitions of risky behavior depending on the field of research. While in the economic view, risk is defined in terms of the variability of possible monetary outcomes, in the clinical literature, the risk is generally defined as exposure to possible loss or harm (Schonberg, Fox, & Poldrack, 2011). Turner et al. (2004) described risk-taking behavior further as either a socially unacceptable volitional behavior with a potentially negative outcome in which precautions are not taken, such as speeding, drinking and driving, drugs abuse, unprotected sex and so on.
There are on average 43 g of sugar and 355 mL can of soda please calculate the molarity of sugar in the can of soda the molar mass of sugar is 342.2 g/mol
Explanation:
Given :
Amount of solute - sucrose (C12H22O11) = 41 g
Amount of solvent -soda = 355-mL
Molarity of the solution with respect to sucrose= ?
Molarity(M) is a unit of concentration measuring the number of moles of a solute per liter of solution. The SI unit of molarity is mol/L.
Formula to find the molarity of solution :
Molarity =
Amount of solvent is given in mL, let’s convert to L :
1 L = 1000 mL
Therefore, 355 mL in L will be :
= 0.355 L
We have the amount of solute in g, let’s calculate the number of moles first :
Number of moles (n) =
Molar mass of C12H22O11 = 342.29 g/mol.
Therefore, n =
= 0.119 moles.
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.
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
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.
