Answer:
When an organism dies, it is usually destroyed by other forms of life and by weathering processes. On rare occasions some body parts—particularly hard ones such as shells, teeth, or bones—are preserved by being buried in mud or protected in some other way from predators and weather. Eventually, they may become petrified and preserved indefinitely with the rocks in which they are embedded. Methods such as radiometric dating—measuring the amounts of natural radioactive atoms that remain in certain minerals to determine the elapsed time since they were constituted—make it possible to estimate the time period when the rocks, and the fossils associated with them.
If a substance has a half life of 58 years and starts with 500 g radioactive, how much remains radioactive after 30 years?
Answer:
A = 349 g.
Explanation:
Hello there!
In this case, since the radioactive decay kinetic model is based on the first-order kinetics whose integrated rate law is:
[tex]A=Ao*exp(-kt)[/tex]
We can firstly calculate the rate constant given the half-life as shown below:
[tex]k=\frac{ln(2)}{t_{1/2}} =\frac{ln(2)}{58year}=0.012year^{-1}[/tex]
Therefore, we can next plug in the rate constant, elapsed time and initial mass of the radioactive to obtain:
[tex]A=500g*exp(-0.012year^{-1} *30year)\\\\A=349g[/tex]
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WILL GIVE BRAINLYEST.
Part C is what I need help with I was just showing the other answers I got for you if it would help.
Question: Which time shows the highest composition of all green house gasses? Comment on any quantitative comparisons with the ice age data.
Answer:
Today has the highest composition of greenhouse gases
Explanation:
Greenhouse gases have been linked to the rise in the temperature of the earth. they are believed to trap infrared ray close to the earth surface thereby causing a steady rise in the temperature of the earth, a phenomenon that has been widely called global warming.
The concentration of greenhouse gases in the atmosphere today ranks highest among other ages due to anthropogenic activities.
During the ice ages, the concentration of greenhouse gases was slightly higher (especially C02) due to natural feedback mechanisms and not due to anthropogenic activities.
Which object will experience the strongest gravitational attraction to Earth?
A. a car
B. a notebook
C. a desk
D. a bowling ball
Answer:
A
Explanation:
The strength of the gravitational force between two objects depends on mass and distance. The object with the greatest mass would be the car.
Calculate the heat gained when 20.1 g ice at - 12.5 degrees * C is heated to liquid water 55.2 degrees * C
Answer:
66.8
Explanation:
Calculate that is what I did.
have a good day!
Which statement explains why carbon-14 dating cannot be used to date ancient rocks?
O Carbon-14 decays at a varying rate.
O Carbon-14 decays quickly leaving the amount too small to measure.
O Carbon-14 can be used only to date the remains of organisms.
O Carbon-14 has a half-life that is much longer than potassium.
Answer: Carbon-14 decays quickly leaving the amount too small to measure.
Explanation:
Answer:
b
Explanation:
i did it
How many grams of sodium phosphate are formed by the reaction of 10 g of sodium with phosphoric acid?
Answer:
23.8g of sodium phosphate are formed
Explanation:
Based on the reaction of sodium, Na, with phosphoric acid, H₃PO₄:
3Na + H₃PO₄ → Na₃PO₄ + 3/2 H₂
3 moles of sodium produce 1 mole of sodium phosphate
To solve this question we must find the moles of sodium in 10g. Using the chemical reaction we can find the moles -And the mass- of sodium phosphate produced, as follows:
Moles Na -Molar mass: 22.99g/mol-
10g * (1mol / 22.99g) = 0.435 moles Na
Moles Na₃PO₄:
0.435 moles Na * (1mol Na₃PO₄ / 3mol Na) = 0.145 moles Na₃PO₄
Mass Na₃PO₄ -Molar mass: 163.94g/mol-
0.145 moles Na₃PO₄ * (163.94g/mol) =
23.8g of sodium phosphate are formed(4x972)+(76.4x29.3)-(12x7)
solve using significant figures please ASAP
Graphene is made of pure _______________.
Answer:
Graphene is made of pure carbon.
Explanation:
It is a material in which the carbon atoms are arranged in a single layer, creating a honeycomb pattern. It should be stressed that this layer of carbon is only one atom thick, although some authors consider up to ten layers of carbon to be graphene.
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A 1.0 g sample of which substance contains the largest
number of molecules?
Answer:
Hydrogen (since this is all the info I'm working with)
Explanation:
Since we need to know how which substance has the most amount of molecules, we would need to look at the Atomic masses of these elements. Hydrogen has an atomic mass of 1.01g/mol whereas something like oxygen has an atomic mass of 16.00g/mol. Judging this, we can determine since a mole is made up of 6.02*10^23 molecules(Avogadro's number), and we have 1/1.01grams of hydrogen, we can deduce that Hydrogen would contain the largest amount of molecules
You mix two amino acids together: glu and ser. If they reacted, how many different dipeptides would you expect to get? List them.
I'm really struggling with amino acids, so any help is appreciated! I won't be clicking any links, though.
Answer:
Answers 1. An amide linkage between the carboxyl group of one amino acid and the amine group of the other amino acid. 2. An ester is a compound formed from the reaction of a carboxylic acid and an alcohol. ( I apologise, I cant figure out number 3.. )
Describe the motion of particles in a
solid compared with a liquid or gas.
Mr. Romeo wants to make a solution of NaOH. He measures out 97.68 grams and puts it into 3 liters
What is the molarity of the solution he created? Round to 2 Decimal points
Answer: Molarity of the solution is 0.813 M.
Explanation:
Given : Mass of NaOH = 97.68 g
Volume of solution = 3 L
The molar mass of NaOH is 39.99 g/mol. Hence, moles of NaOH are calculated as follows.
[tex]No. of moles = \frac{mass}{molar mass}\\= \frac{97.68 g}{39.99 g/mol}\\= 2.44 mol[/tex]
Molarity is the number of moles of solute present in a liter of solution. Therefore, molarity of given solution is calculated as follows.
[tex]Molarity = \frac{no. of moles of solute}{Volume (in L)}\\= \frac{2.44 mol}{3 L}\\= 0.813 M[/tex]
Thus, we can conclude that molarity of the solution is 0.813 M.
Wing practice problems:
1. How many grams of water could freeze at 0°C when 525 KJ of energy is released?
Answer:
g x 334 J/g = 3340J or 3.34kJ.
Explanation:
The energy required for one gram of a solid to melt without experiencing any temperature change is known as the heat of fusion. 3.34 KJ of energy is released.
What is heat of fusion ?The most typical illustration is when solid transforms into liquid water. The molecules within the substance become less structured as a result of this process, which is also known as melting or heat of fusion.
The change in enthalpy ( H ) that occurs when a substance transforms from a solid to a liquid state.
The amount of energy required for one gram of a liquid to evaporate (boil) without a change in pressure is known as the heat of vaporization.
Q = gram × 334 J / g
= 3.34 KJ
Thus, at 0°C when 525 KJ of energy released is 3.34 KJ.
To learn more about heat of fusion follow the link below;
https://brainly.com/question/14053504
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answer asap pls i give brainliest
Answer:
B. Revolution is a planet's movement around the sun causing four seasons the occur. Rotation is the spinning of the planet on its axis causing day and night.
As time passes, which of these is decreasing?
es )
A)
amplitude
B)
crest
trough
D)
wavelength
Answer:
Wavelength (D)............
Answer:
A
Explanation:
the amplitude is measured from the dotted line to the top of the crest. Looking at the picture the amplitude gets smaller
Solve for 1. Enter the solutions from least to greates (x + 3)2 - 4= 0 lesser ,greater
Answer:
Explanation:
If you would like to solve 1/(x + 3) = (x + 10)/(x - 2), you can do this using the following steps:
1/(x + 3) = (x + 10)/(x - 2)
1 * (x - 2) = (x + 10) * (x + 3)
x - 2 = x^2 + 3x + 10x + 30
0 = x^2 + 13x + 30 - x + 2
0 = x^2 + 12x + 32
0 = (x + 8) * (x + 4)
1. x = -8
2. x = -4
Which is composed of alkenes? welding torch fuel polystyrene cups propane gas degreaser containing hexane
Answer:
welding torch fuel
Explanation:
Alkenes are chemical compounds formed by a carbon atom and a hydrogen atom. They have an open chain with double bonds between two carbon acts. They are widely used in the composition of fuels, such as welding torch fuel and have as main characteristics the solubility in solvents, the insolubility in water, high melting and boiling point and the absence of colors.
Welding torch fuel is composed of alkenes. The alkenes comprise a series of compounds that are composed of carbon and hydrogen atoms with at least one double bond in the carbon chain.
What are alkenes?Alkenes are a homologous series of hydrocarbons that contain a carbon-carbon double bond.
The number of hydrogen atoms in an alkene is double the number of carbon atoms, so they have the general formula [tex]C_nH _2 _n[/tex].
For example, the molecular formula of ethene is [tex]C _2 H _4[/tex] , while for propene it is [tex]C _3 H _6[/tex].
Alkenes are chemical compounds formed by a carbon atom and a hydrogen atom.
They have an open chain with double bonds between two carbon acts.
They are widely used in the composition of fuels, such as welding torch fuel and have as main characteristics the solubility in solvents, the insolubility in water, high melting and boiling point and the absence of colors.
Hence, the Welding torch fuel is composed of alkenes.
Learn more about the alkenes here:
https://brainly.com/question/13910028
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What is the molarity of a 511 ml solution containing
205 mg of NH3?
401M 0.0235M 0.401M 0.0000235M
how many torr is 2.7 atm?
2.7 atm = ? torr
Answer:
2.7 atm = 2052 torr
I hope this helps you.
Answer:
2052 torr
Explanation:
Multiply 2.7 atm by the conversion factor to torr which is 760 torr = 1 atm
HELP PLEASE 40.0 grams of salt are dissolved in 100. grams of water. The solution is how many grams?
Answer:
The mass of the solution is 140 grams.
Explanation:
The mass of the solution is given by the sum of the solute's mass and the solvent's mass:
[tex] m_{sol} = m_{ste} + m_{svt} [/tex]
Where:
[tex] m_{sol} [/tex]: is the mass of the solution
[tex]m_{ste}[/tex]: is the mass of the solute
[tex]m_{svt} [/tex]: is the mass of the solvent
The solute is the salt (40.0 g) and the solvent is the water (100 g), so:
[tex] m_{sol} = m_{ste} + m_{svt} = 40 g + 100 g = 140 g [/tex]
Therefore, the mass of the solution is 140 grams.
I hope it helps you!
Question 26 of 33
How many energy levels contain electrons in an atom of calcium (Ca)?
The Periodic Table
A. Three
B. Four
C. One
D. Two
Answer:
B
Explanation:
four electron in atom in cal
This attached picture !!
How many kJ are needed to heat 300.0 g of ice at -5.00°C into steam at 100.°C?
Answer:
Q = 63.9 kJ
Explanation:
Given that,
Mass of ice, m = 300 g
We need to find the heat needed to heat the given amount of ice at -5.00°C into steam at 100.°C
The specific heat of ice, c = 2.03 J/g °C
The formula for heat needed is given by :
[tex]Q=mc\Delta T\\\\Q=300\times 2.03\times (100-(-5))\\\\Q=63945\ J\\\\Q=63.9\ kJ[/tex]
So, 63.9 kJ of heat is needed.
You need to prepare .200M solution of hydrochloric acid (HCl). If you took out .830ml of the 12.0M stock solution. How much water must you add to make the .200M diluted solution?
Answer:
You must add 48.97 mL of water to make the 0.200 M diluted solution.
Explanation:
In chemistry, dilution is the reduction in concentration of a chemical in a solution. In other words, it is the process of reducing the concentration of solute in solution, simply adding more solvent to the solution.
In a dilution, the quantity or mass of the solute is not changed but only that of the solvent. As only solvent is being added, by not increasing the amount of solute the concentration of the solute decreases.
The expression for the dilution calculations is:
Cinitial* Vinitial = Cfinal* Vfinal
In this case:
Cinitial= 12 MVinitial= 0.830 mLCfinal= 0.200 MVfinal= ?Replacing:
12 M*0.830 mL= 0.200 M*Vfinal
Solving:
[tex]Vfinal=\frac{12 M*0.830 mL}{0.200 M}[/tex]
Vfinal= 49.8 mL
Since 0.830 mL is the volume you initially have of HCl, the amount of water you must add is:
49.8 mL - 0.830 mL= 48.97 mL
You must add 48.97 mL of water to make the 0.200 M diluted solution.
How much heat is gained by 1.25 grams of ice?
Answer:
Heat gained by 1.25 grams of ice is 250 joules
Explanation:
As we know
[tex]Q = mc\Delta[/tex]T
Where
[tex]\Delta[/tex]T is the change in temperature
Water freezes at 273.15 K/0 degree Celsius, and it boils at 373.15 K/00 degree Celsius,
[tex]\Delta[/tex]T
m is the mass in grams
c is the specific heat of water (ice) = 2.05 joules/gram
Substituting the given values, we get -
[tex]Q = 1.25 * 2.0 * 100\\Q = 250[/tex]Joules.
State of matter
A gas made up of homonuclear diatomic molecules escapes through a pinhole 3.98 times as fast as oxygen gas. Write the Chemical formula of the gas.
Answer:
H₂
Explanation:
To solve this question we must find, as first, find the molar mass of the homonuclear diatomic gas using Graham's law. With the molar mass we can identify this gas
Graham's law:
[tex]\frac{V_a}{V_b} =\sqrt{\frac{m_B}{m_A} }[/tex]
Where V is the speed of the gases and m the molar mass of those:
As Va is 3.98 times Vb (And mB is molar mass of oxygen gas = 32g/mol)
[tex]3.98 =\sqrt{\frac{32g/mol}{m_A} }[/tex]
15.84 = 32g/mol / mA
mA = 2.02g/mol
As is a homonuclear diatomic gas, the molar mass of the atom is 1.01g/mol. Thus, the gas is:
H₂If I held a heavy rock up 6 feet from the ground and kept it completely still, what kind of energy does it have?
Answer:
kenetic
Explanation:
<3
Which type of star has the greatest temperature on the HR diagram? Question 7 options: Red Supergiants Main Sequence White Dwarfs Red Giants
Answer:
Red supergiant
Explanation:
Their core is the hottest.
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Which type of star has the greatest temperature on the HR diagram? Question 7 options: Red Supergiants Main Sequence White Dwarfs Red Giants
Answer:
Red Super Giants
Explanation:
Beacuse of the of their size, the core temperature is more hotter then White Dwarfs and Red Giants.
Answer:
Red Super Giants
Explanation:
Their core is the hottest.
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A compound has an empirical formula of CH20. What is its molecular formula, if its molar mass is 360 g/mol?
a. C6H12O6
b. C12H24O12
Answer:
a
Explanation:
A actual molecule of glucose contains six carbon atoms, twelve hydrogen atoms, and six oxygen atoms.
Answer:
B.
Explanation: