Answer:
yo m ok mama
Explanation:
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An isotope of Cesium -137 has a half-life of 30 years. If 1.0 g of Cesium – 137 disintegrates over a period of 60 years, how many grams of Cesium- 137 would remain?
Answer:
Explanation:
Radioactive decay follows the equation:
Ln [A] = -kt + ln [A]₀
Where [A] is amount of isotope after time t: Our incognite,
k is rate constant: ln 2 / Half-life = 0.0231 years⁻¹
t are 60 years
[A]₀ is initial amount of isotope: 1.0g
Replacing:
Ln [A] = -kt + ln [A]₀
Ln [A] = -0.0231 years⁻¹*60 years + ln 1.0g
ln [A] = -1.386
[A] = 0.25g
Help please If there are 10 moles of HCl gas occupying 15L at 350°C, what is the pressure? Be sure to show the setup and
the final answer and unit.
Show Your Work
Answer:
P = 34.1 L
Explanation:
Given data:
Number of moles = 10 mol
Volume occupy = 15 L
Temperature = 350°C
Pressure of gas = ?
Solution:
The given problem will be solve by using general gas equation,
PV = nRT
P= Pressure
V = volume
n = number of moles
R = general gas constant = 0.0821 atm.L/ mol.K
T = temperature in kelvin
Now we will convert the temperature.
350+273 = 623 K
by putting values,
P×15 L = 10 mol ×0.0821 atm.L/ mol.K ×623 K
P = 511.48atm.L/15L
P = 34.1 L
What is the frequency of a photon with an energy of 3.38 x 10-19 J?
[tex]\huge\boxed{5.1x[tex]10^{14}[/tex]Hz}[/tex]
_____________________________________DATA:E = [tex]3.38 x 10^{-19}[/tex]
h = [tex]6.625x10^{-34}[/tex]
f = ?
_____________________________________SOLUTION:Energy of Photon is given by,
E = hf
Rearrange the equation,
f = [tex]\frac{E}{h}[/tex]
where,
E = energy
h = planck's constant
f = frequency
------------------------------------------------------------------------------------------------------------
Substitute the variable in the equation,
f = [tex]\frac{3.38x10^{-19}}{6.62x10^{-34}}[/tex]
Simplify the equation,
f = 5.10 x 10^14 Hz
_____________________________________Best Regards,'Borz'
Answer:
b. 5.10 x 10^14 Hz
Explanation:
What color are the stars on the diagram with the lowest surface temperatures?
Answer:
red supergiants is the answer
Dating of Rock Layers
Answer all 12 questions relating to the images below
English (US)
100
Answer:
I'm sorry, we need the image to answer it.
Explanation:
arrange the following in order of increasing mass . a. 16 water molecules b. 2 atoms of lead 3. 5.1*10^-23
After pollen grows on a tube down the style,___
Answer:
as soon as the pollen reaches the stigma after the pollen grain descends down the style when the pollen tube grows into the ovule when the seed germinates
Explanation:
Which method of heat transfer is the person in the picture below most worried about?
Radiation
Conduction
Convection
Answer:
Radiation ...........
[tex]\huge\boxed{Conduction}[/tex]
_____________________________________Conduction:Conduction is the transfer of heat when two things come in contact with each other. The energy transfer is from hotter body to the colder body.
x---------------------------------------------x
Fire Walking:There is a trick behind fire-walking. When the coal burns, after sometime there is a layer of ash on the surface of the coal which blocks the radiation. So the transfer of heat is not possible from radiation. Conduction is the only way possible. The person's feet and coal both are poor conductor of heat so if we walk quickly i.e. there is minimal time of contact with the coal, it will just feel a little warm. As the person start walking on the coal, It has to do it quickly, that way Person will feel its sole warming up but it is not that hot because of the layer of ash and poor conductance, after few steps the ash also sticks on to the sole of the person which makes kind of double layers of ash. So the only way for heat transfer is CONDUCTION.
_____________________________________Best Regards,'Borz'Directions: Read through each scenario and identify the independent variable, dependent variable, and the control.
Question 1
1 pts
Rob is in charge of waxing the floor at the local mall. He wants to test a new brand of floor wax called
Squeaky Clean. Rob waxes 20 floor tiles with Squeaky Clean and 20 tiles with the original wax brand.
After one week he counts the number of scratches on the floor. What is the independent variable?
number of floor scratches
brand of floor wax
20 tiles with original brand wax
Answer:
The correct answer is - brand of floor wax.
Explanation:
The independent variable is the variable or the factor in an investigation which is manipulated or change in the experiment and affects the dependent variable and produces a various result.
In this investigation, there are different brands of the floor was are the independent variable as they are changed to see the effect on the scratches on the floor on 20 tiles for each brand.
How many electrons are located in the outermost energy level in the Bohr model of a boron atom? hint it not 4
4
3
2
1
Which of these changes to a modern lifestyle would promote the
development of more-sustainable practices in the world food system?
O A. Switching from chicken to beef
B. Eating fewer processed foods
O C. Buying tropical fruits
D. Eating fresh vegetables year-round
Eating fewer processed foods would promote the development of more-sustainable practices in the world food system.
What are Processed food?
This is the food which has undergone some degree of alteration during preparation such addition of preservatives etc.
Eating less of it will ensure that more sustainable practices in the world food system are promoted.
Read more about Processed food here https://brainly.com/question/21201084
#SPJ2
How to do this question plz answer me
Answer:
dissolved
Explanation:
The figure shows sodium chloride is in solution. It gets that way by being dissolved.
paragraph on water cycle
Answer:
The water cycle or hydrologic is a continuous cycle where water evaporates, travels into the air and becomes part of a cloud, falls down to earth as precipitation, and then evaporates again. ... These areas are usually close to oceans or large bodies of water that allow more water to evaporate and form clouds.
Explanation:
State the number of degrees of longitude that separates New York City from Denver, Colorado between these two cities.
Answer:
The number of degrees of longitude that separates New York City from Denver, Colorado is 30.9843 degrees longitude
Explanation:
The longitude of New York City is 74.0060° W
The latitude of New York City is 40.7128° N
The longitude of Denver, Colorado is 104.9903°W
The latitude of Denver Colorado is 39.7392°N
Therefore, the difference the number of degrees of longitude that separates New York City from Denver, Colorado is 104.9903 - 74.0060 = 30.9843°.
calculate the ph of a solution whose(oh^-) is 4.583*10^-5 mole dm cube (pkw=14)
pH of solution = 9.661
Further explanationpH is the degree of acidity of a solution that depends on the concentration of H⁺ ions. The greater the value the more acidic the solution and the smaller the pH.
pH = - log [H⁺]
So that the two quantities between pH and [H⁺] are inversely proportional because they are associated with negative values.
pOH=-log[OH⁻]
[tex]\tt pOH=-log[4.583\times 10^{-5}]\\\\pOH=5-log~4.583=4.339[/tex]
pH+pOH=pKw
[tex]\tt pH=14-4.339\\\\pH=9.661[/tex]
Why is NCl3 not soluble in water?
Answer:
Explanation:
NCl3 does not dissolve in water because it is a nonpolar molecule which is different with water. NCl3 is nonpolar due to the difference in electronegativities between 3 atoms of Cl and 1 atom if N2.
Answer:
A polar solute dissolves into a polar solvent and a non-polar compound dissolves into a non-polar solvent, this rule is known as "like dissolves like".
the number of molecules in 7g nitrogen
Answer:
the number of molecules in 7g nitrogen
Ans) 7 gram of Nitrogen contains 1.5×10^23 molecules =1.5e+23
helpppppp i hate chemistry
I will give brainiest who helps me with the correct answer
I promise
5. Name the compound which contain Strontium, Fluorine, and Oxygen.
Options:
Strontium fluorate
Strontium fluoride
Strontium chlorate
Strontium fluorine
Answer:
The first option: Strontium Fluorate.
Explanation:
because Fluorine and oxygen combines to make fluorate, Strontium stays the same.
p.s: i need help in geo and there's an exam tomorrow.
Hydrogen bond is not formed by 1) oxygen 2) nitrogen 3) chlorine
PLEASE HELP!!!
Answer:
Input work is the work done on a machine as the input force acts through the input distance. This is in contrast to output work which is a force that is applied by the body or system to something else. Output work is the work done by a machine as the output force acts through the output distance.Jan 15, 2020 bahsgsh bvshgs d hg
Butane and methyl propane are an example of a pair of
Momentum is mass times
A. acceleration
B. velocity
C. distance
B. velocity
This is the answer
When propane is reacted in the presence of oxygen gas, the products of this combustion reaction are: A. CO + H2O B. CO2 + H2O C. C2H4 + H2O D. CH4 + H2O
Answer:
B. CO2 + H2O
Explanation:
Propane is an hydrocarbon as it contains only v=carbon and hydrogen atoms.
Whenever an hydrocarbon reacts with oxygen or undergoes a combustion reaction, two products are always formed only,
These two products are;
Carbon dioxide (CO2) and water (H2O)
This means the correct option is option B.
HELP ME PLEASEEE -------------------------------- BRAINLY !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Answer:
help with what tho-
Explanation:
state two uses of graphite which depends on the above properties
1. What part of the human body has the same role as the power source in a computer?
2.What part of the human body has the same role as the keyboard or the mouse on a computer?
Answer:
The heart
Hand
Explanation:
The part of the human body that has the same role as the power source in a computer is the heart. A power source in a computer provides energy that powers the whole system.
The human heart provides the pumping action for the circulatory system. Just like current passes through wires in a computer by energy from the power source, the human heart pumps blood throughout the body in a like manner. Without the pumping action of the heart, the human body is dead.Also, keyboard and mouse are input devices. They are used to give instruction and perform certain tasks on the computer system.
The human body can also carryout tasks by using the hand. Objects are moved from one place to another just as you drag an icon using the mouse. We type word processors using information from the keyboard, also, we are able write using pen on paper.How are solutions classified? Give an example of each.
Which of the following does not apply to water molecules?
Water molecules are polar
Water has cohesive properties
Water is less dense as a solid than a liquid
Water is not a very good solvent
Answer:
It is the last one.
Explanation:
Water molecules are polar, they have cohesive properties, and water is less dense when it is solid than when it is a liquid, that is why ice floats in liquid water. However, water is a very good solvent, it can dissolve many solids, including sugar, salt, and other hydrophilic substances.
describe a habitat of giraffe or an elephant(i prefer the giraffe tho, and please make it reasonable)
Answer: Savanna, Woodland, or Grassland.
Giraffes eat new shoots and leaves, their habitat needs to have a good supply of trees -- they flock towards acacia trees in particular. Giraffes use their extremely long legs, necks and tongues to browse mainly from the thorns on the acacia tree. The tongue and the inside of the mouth are lined with tough tissue that protects against the thorns.
Given the following equation,
HCl aq) + NaOH aq
NaClaq) + H2O(l)
How many moles of H20 will be produced if there are 5 moles of HCI?
Answer:
5 moles
Explanation:
Given data:
Number of moles of HCl = 5 mol
Number of moles of H₂O produced = ?
Solution:
Chemical equation:
HCl + NaOH → NaCl + H₂O
Now we will compare the moles of HCl with H₂O.
HCl : H₂O
1 : 1
5 : 5
5 moles of water will be produced.
Which of the following sets of forces acting on an object will result in the object moving?
5 Newtons Up and 5 Newtons Down
31 Newtons Left and 32 Newtons Right
0 Newtons Up and 0 Newtons Down
9 Newtons Left and 9 Newtons Right
Answer:
31 N left and 32 N right because
Explanation:
It’s the only one movement because when you subtract them there’s still 1 left