Answer:
Probability
Explanation:
Radioactive isotope X has a half-life of 500,000 years. This isotope may be found in some types of volcanic rocks. A particular sample of volcanic rock taken from a layer that covered up some of the earliest known human-like footprints contains 0.125 mg of isotope X. The volcanic rock sample originally contained 8.00 mg of isotope X. How long ago were these footprints made. I need the equation. Thanks. please I am stuck on this question. PLEASE
Answer: The footprints were made [tex]2.99\times 10^6years[/tex] years long ago.
Explanation:
Radioactive decay follows first order kinetics.
Half-life of isotope X= 500,000 years
[tex]\lambda =\frac{0.693}{t_{\frac{1}{2}}}=\frac{0.693}{500000}=0.00000139year^{-1}[/tex]
The equation for first order kinetics is :
[tex]N=N_o\times e^{-\lambda t}[/tex]
N = amount left after time t = 0.125 mg
[tex]N_0[/tex] = initial amount = 8.00 mg
[tex]\lambda[/tex] = rate constant
t= time
Putting the values we get:
[tex]0.125=8.00\times e^{- 0.00000139years^{-1}\times t}[/tex]
[tex]0.0156=e^{- 0.00000139years^{-1}\times t}[/tex]
[tex]t=2.99\times 10^6years[/tex]
The footprints were made [tex]2.99\times 10^6years[/tex] years long ago.
1. Calculate the number of moles in each of the following masses:
a. 64.1 g of aluminum ans: 2.38 mol Al show work
Answer:
2.38 mol of Al
Explanation:
To find the number of moles in a substance, you simply divide by the atomic mass. In this case, the conversion table would look as follows:
[tex]\frac{64.1 g}{1}[/tex] * [tex]\frac{1 mol}{26.98 g}[/tex]
The gram units cancel, and you are left with the answer of about 2.38 moles of Aluminum.
During which process of the water cycle does water change from gas to liquid
Which of the following is a chemical property of a sheet of paper?
A. The paper can be burned.
B. The paper can be crumbled.
C. The paper does not attract a magnet.
D. The paper does not conduct electricity.
Answer:
A
Explanation:
Flammability is a chemical property. The paper crumbling would be a physical property. The inability to attract a magnet or conduct electricity would be considered electrical properties
A train travels at an average speed of 25 miles per hour. How long does it take the train to travel 2000 miles?
nevermind. I was wrong. I didn't see the other answers
How much energy is required to heat 0.24 KG lutetium from 296.2K to 373.5 K? The specific heat for lutetium is 0.154 J/g-K
Answer:D. 2857 joules
Explanation:
Not going to lie I guessed but got it right
According to specific heat capacity, 3596.208 joules of energy is required to heat 0.24 kg of lutetium from 296.2 K to 373.5 K.
What is specific heat capacity?Specific heat capacity is defined as the amount of energy required to raise the temperature of one gram of substance by one degree Celsius. It has units of calories or joules per gram per degree Celsius.
It varies with temperature and is different for each state of matter. Water in the liquid form has the highest specific heat capacity among all common substances .Specific heat capacity of a substance is infinite as it undergoes phase transition ,it is highest for gases and can rise if the gas is allowed to expand.
It is given by the formula ,
Q=mcΔT
Substitution in above formula gives, q= 0.24×154×97.3=3596.208 Joules.
Thus, 3596.208 joules of energy is required to heat 0.24 kg of lutetium from 296.2 K to 373.5 K.
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is sandy, silt, or clay loam better? and why?
does this picture show a physical or chemical change?
Answer:
Those photos are a chemical change
14.600 oz = ____g
(HELP ME PLEASE)
Answer:
The answer is 414.64 g the other answer is wrong
Explanation:
I took this assignment and got this question right
helppppppppppppppppppppppppppppppppppppppppppppppppp
Answer: it is a
Explanation:
2. Mixtures can be solid, liquid or gas. It can be homogeneous or
heterogeneous and are made up of two or more components. Which of
the following mixtures where components are not visible??
Answer:
A solution is a special type of homogeneous mixture where the ratio of solute to solvent remains the same throughout the solution and the particles are not visible with the naked eye, even if homogenised with multiple sources.
Explanation:
Mixtures can be either homogeneous or heterogeneous': a mixture in which constituents are distributed uniformly is called homogeneous, such as salt in water, otherwise it is called heterogeneous, such as sand in water.
which statement describes what happens inside
a liquid thermometer that shows an increase in
temperature?
a. the volume of the liquid decreases because
of an increase in kinetic energy.
b. the movement of the particles decreases
because of a decrease in kinetic energy. .
c. the volume of the liquid increases because
the movement of the particles decreases.
d. the movement of the particles increases
because of an increase in kinetic energy.
Answer:the volume of the liquid increases
Explanation:
How do the rock cycle and the carbon cycle relate to each other?
Answer:
Through a series of chemical reactions and tectonic activity, carbon takes between 100-200 million years to move between rocks, soil, ocean, and atmosphere in the slow carbon cycle. ... The acid dissolves rocks—a process called chemical weathering—and releases calcium, magnesium, potassium, or sodium ions.
Which two models can be classified as elements
Answer:
First One And Third Pls Mark Brainlest
Explanation:
which describes the substances that form covalent bonds
Answer:
both Non metal's G
Explanation:
i did the test
Which has the least potential energy?
gases
liquids
solids
Answer
The answer is SOLIDS
Explanation:
PLeaseee Help Asap!!!
What kinds of organisms have "naked" DNA?
Answer:
The DNA in prokaryotes is naked DNA.
Explanation:
Prokaryotes have cell walls which are a network of fibres that provides the cell with strength and rigidity. This network in the cell wall allows the cell to be freely permeable. These differ from eukaryotes which have a nucleus containing genetic information (DNA).
Is Magnesium less reactive than Aluminum ? Yes or No
Answer:
The answer is no
Answer:
yes
Explanation:
some metals are reactive than others. Example: (a) Magnesium is more reactive than silver. (b) Magnesium reacts with oxygen but silver doesn't because magnesium is more reactive than silver.
please mark me brainliest hope this helps! god bless
If you worked at a job for 9.00/hour, what type of correlation is the number of hours worked and your take-home pay?
Answer:
There is a linear correlation between the number of hours worked and take-home pay. And more exactly, a direct proportionality. [tex]C = 9\cdot t[/tex]
Explanation:
From statement we deduce that amount of hours worked ([tex]t[/tex]) (Independent variable, measured in hours) is directly proportional to take-home pay ([tex]C[/tex]) (dependent, measured in monetary units), since proportionality ratio is constant and, therefore, there exists a linear correlation between both variables. That is:
[tex]C \propto t[/tex]
[tex]C = k\cdot t[/tex] (Eq. 1)
Where [tex]k[/tex] is the proportionality ratio, measured in monetary units per hour. If we know that [tex]k = 9\,\frac{m.u.}{h}[/tex], then the resulting correlation is:
[tex]C = 9\cdot t[/tex]
There is a linear correlation between the number of hours worked and take-home pay.
PLEASE APEZ HELP I DONT UNDERSTAND
A teacher placed a plastic cup of warm coffee with a lid in the freezer.
Which statement describes the frozen coffee in comparison with the warm
coffee?
A. The amount of coffee is the same.
B. The speed of the coffee molecules has increased.
C. The temperature of the coffee has increased.
D. The arrangement of the coffee molecules is the same.
Answer: The answer is A
Explanation:.
True or False?
Solubility and melting point are two examples of physical properties.
Answer: True
Explanation:
Solubility is a physical property. The reason is because it can be determined by simple observation and does not change the chemical composition of the material. If the material is soluble, the solubility is the maximum amount of material that dissolves in a solvent at a given temperature.
A physical property is a characteristic of matter that is not associated with a change in its chemical composition. Familiar examples of physical properties include density, color, hardness, melting and boiling points, and electrical conductivity.
Answer: True
Explanation: These are both examples of physical properties
What are the solvent and solute in a solution containing 100 grams of ethanol and 3 grams of sucrose?
Answer: I think the ethanol in the solute and the sucrose is the solvent. Hope this helps!
Explanation: i learned this last year I think it is right?
A solvent is a chemical that dissolves a solute to produce a uniform solution. A solute is a substance that dissolves in a solvent, resulting in a homogeneous mixture. The solute is sucrose, and the solvent is ethanol.
What is meant by solution ?A solution is a well-mixed solution in a solvent of one or more dissolved solutes. A solute is a substance that dissolves another substance, creating a continuous medium. A solute is a substance that dissolves in a solvent, resulting in a homogeneous mixture.A solution is formed when one substance dissolves or degrades into another. A solute is any substance that dissolves to form a solution. A solvent is a chemical that is used to disperse a solute. The solute in a sugar-water solution is sugar, and the solvent is water. A solution is a homogeneous mixture of two or more particles with diameters less than one Nano meter.To learn more about Solution, refer to:
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How much force is required to accelerate a 12 kg mass at 5 m/s2?
Answer:
The answer is 60 NExplanation:
The force acting on an object given it's mass and acceleration can be found by using the formula
force = mass × acceleration
From the question we have
force = 12 × 5
We have the final answer as
60 NHope this helps you
if an object has a mass of 30 grams and a volume of 6 cubic cm. what is its density
Answer:
5
Explanation:
mass/volume = density
30/5 = 5
.) If a solution had a pH level of 13.2, it would be considered a:
O A. strong base
O B. weak base
O C. strong acid
O D. weak acid
How many moles (of molecules or formula units) are in each sample?
A) 32.66 g CF2Cl2
B) 24.2 kg Fe (NO3) 2
C) 0.5912 g C8H18
D) 104 kg CaO
Express all answers to 4 sig figs
Answer:
A = 1.627 ×10²³ molecules of CF₂Cl₂.
B = 809.4 ×10²³ molecules of Fe(NO₃)₂.
C = 0.03117 ×10²³ molecules of C₈H₁₈.
D= 1116 ×10²³ molecules of CaO.
Explanation:
A)
Given data:
Mass of CF₂Cl₂ = 32.66 g
Number of moles = ?
Number of molecules = ?
Solution:
Number of moles = mass/ molar mass
Number of moles = 32.66 g/ 120.9 g/mol
Number of moles = 0.2701 mol
Number of molecules:
1 mole = 6.022×10²³ molecules
0.2701 mol×6.022×10²³ molecules / 1mol = 1.627 ×10²³ molecules of CF₂Cl₂.
B) Given data:
Mass of Fe(NO₃)₂ = 24.2 Kg (24.2×1000 = 24200 g)
Number of moles = ?
Number of molecules = ?
Solution:
Number of moles = mass/ molar mass
Number of moles = 24200 g/ 180 g/mol
Number of moles = 134.4 mol
Number of molecules:
1 mole = 6.022×10²³ molecules
134.4 mol×6.022×10²³ molecules / 1mol =809.4 ×10²³ molecules of Fe(NO₃)₂.
C) Given data:
Mass of C₈H₁₈= 0.5912 g
Number of moles = ?
Number of molecules = ?
Solution:
Number of moles = mass/ molar mass
Number of moles = 0.5912 g/ 114.22 g/mol
Number of moles = 0.005176 mol
Number of molecules:
1 mole = 6.022×10²³ molecules
0.005176 mol×6.022×10²³ molecules / 1mol =0.03117 ×10²³ molecules of C₈H₁₈.
D) Given data:
Mass of CaO = 104 Kg (104×1000 = 104,000 g)
Number of moles = ?
Number of molecules = ?
Solution:
Number of moles = mass/ molar mass
Number of moles = 104,000 g/ 56.1 g/mol
Number of moles = 1854 mol
Number of molecules:
1 mole = 6.022×10²³ molecules
1854 mol×6.022×10²³ molecules / 1mol = 1116 ×10²³ molecules of CaO.
PLEase help i will give brainliest
Consider the information provided in experiment #3 Figure 2. Three different variables are compared for C3H8 (propane) and H2O (water). The strength of the intermolecular forces are responsible for the behavior of the two compounds.
Identify the intermolecular force for the two compounds.
Which one is stronger?
Explain how the strength of intermolecular forces plays a role in at least two of the properties (volatility, boiling point, or surface tension) for C3H8 (propane) and H2O (water).
Cite evidence from the data to explain your reasoning.
Experiment #3: The student follows study #2 with a comparison of propane (C3H8) and water. Volatility is the tendency for a substance to vaporize and it was found that propane vaporizes quickly while water vaporized slowly. Surface tension is a physical property equal to the amount of force per unit area necessary to expand the surface of a liquid. It is this phenomenon which allows a water strider or lizard to run across the surface of water.
Answer:
what kind of school u doin? lol
organize the following location's from the smallest to largest respectively
A.Texas
B.United states
C.North America
D.City of Mission
E.Hidalgo county
What is a polar molecule?
A. A molecule with symmetrical polar covalent bonds
B. A molecule with symmetrical nonpolar covalent bonds
C. A molecule with a negative pole and a positive pole
D. A molecule with two atoms of the same electronegativity
Explanation:
A molecule with a negative pole and a positive pole is called a polar molecule.
(d) A molecule with two atoms of the same electronegativity
What is meant by a polar molecule?A polar molecule is usually formed when the one end of the molecule is said to possess more positive charges and whereas the opposite end of the molecule has negative charges, creating an electrical pole.
What is a polar molecule example? Water (H2O) is a polar molecule. The bonds between hydrogen and oxygen are distributed so that the hydrogen atoms are both on one side of the oxygen atom rather than evenly spaced.Sodium Chloride (NaCl) which is an ionic compound acts as a polar molecule. Usually, the large difference in electronegativities in sodium and chlorine makes their bond polar.Learn more about polar molecule on https://brainly.com/question/11405437
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