Answer:
A. The measure of the amount of space a substance takes up
Explanation:
If the half-life of iodine-131 is 8.0 days, how much of a 100.0 mg sample of it will remain after 32 days? In case you're interested, iodine-131 forms xenon-131 by beta emission/decay. Please enter only a numerical answer and do not write in any units. It is understood that the unit is mg.
Given :
Half-life of Iodine , [tex]t_{0.5}=8 \ days[/tex] .
Initial concentration , [tex][A_o]=100\ mg[/tex] .
To Find :
The amount of sample remains after 32 days .
Solution :
Rate constant is given by :
[tex]k=\dfrac{0.693}{t_{0.5}}\\\\k=\dfrac{0.693}{8}\ s^{-1}\\\\k=0.086625\ s^{-1}[/tex]
Now , by rate law :
[tex][A]=[A_o]e^{-kt}[/tex]
Putting all given values, we get :
[tex][A]=100\times e^{-(0.086625)\times 32}\\[/tex]
[tex][A]=6.25\ mg[/tex]
Therefore , the remaining sample after 32 days is 6.25 mg .
Hence , this is the required solution .
A recycling center must find a way to separate all of the aluminum cans from those made of nickel or iron. What would be a reliable, efficient way to separate them?
Answer:
Use a giant magnet to pick up the iron and nickel ones, leaving the aluminum behind.
Explanation:
Stay safe!
true or false : when a theory has been known for a long time , it becomes a law
False.
It won’t become one if it’s not proven true.
A box has dimensions of 2.0 cm time 4.0 cm times 8.0 cm, what is the volume of the box in milliliters?
Answer:
64 mL.
Explanation:
From the question given above, the dimension of box is:
Dimension = 2 cm × 4 cm × 8 cm
Thus, the volume of the box is:
Volume = 2 cm × 4 cm × 8 cm
Volume = 64 cm³
Finally, we shall convert 64 cm³ to mL. This can be obtained as follow:
Recall:
1 cm³ = 1 mL
Therefore,
64 cm³ = 64 cm³ × 1 mL / 1 cm³
64 cm³ = 64 mL
Therefore, the volume of the box in millilitres (mL) is 64 mL.
How many valence electrons does aluminum (AI) have available for bonding?
1
2
3
4
Which of the following has a negative charge? A.neutrino B.electron C.alpha particles D.gamma rays
Answer:
B. Electrons
Explanation:
Protons have a positive (+) charge.
Neutrons have a neutral (0) charge.
Electrons have a negative (-) charge.
Alpha Particles is a helium atom.
Gamma Rays are radiation.
Neutrino is Quantum Physics.
Need help with this
Answer:
environmentalism I think
Explanation:
...................
Answer:
2nd choice answer
Explanation:
thats ez tbh
what is hydrophytes?
1. Which atom contains exactly 16 neutrons?
A S-33
B P-31
C O-16
D Cl – 35
2. In a mass spectrometer
A Particles with the most mass are deflected the most
B Particles with the least mass are deflected the most
C Particles with the least mass are deflected the least
D All particles are deflected the same
3. Calculate the mass, in grams, of 3.00 moles of carbon.
A 3.00 grams C
B 18.0 grams C
C 36.0 grams C
D 54.0 grams C
4. Calculate the number of moles of aluminum in 65 grams of aluminum?
A 2.4 moles Al
B 5.0 moles Al
C 850 moles Al
D 1800 moles Al
5. Calculate the number of atoms of sodium in a 4.5-gram sample.
A 1.2 x 1023 atoms Na
B 2.5 x 1023 atoms Na
C 1.7 x 10-22 atoms Na
D 3.1 x 1024 atoms Na
Answer:
1. B 2. B 3. C 4. A 5. A
Explanation:
1 Which atom contains exactly 16 neutrons?
Neutrons = Mass Number - Proton
A -33;
Neutrons = 33 - 16 = 17
B P-31
Neutrons = 31 - 15 = 16 Correct option
C O-16
Neutrons = 16 - 8 = 8
D Cl – 35
Neutrons = 35 - 17 = 18
2. In a mass spectrometer, the heaviest particles are least deflected and that with the least mass are deflected the most. The correct option is B.
3. 1 mol of C = 12 grams;
3 mol = x
x = 3 * 12 = 36 grams Correct option is C
4. 1 mol = 27g of Al;
x mol = 65g
x = 65 / 27 = 2.4 moles. Correct option is A.
5. There are 6.022 x 10^23 atoms in 23 grams of sodium;
x atoms in 4.5g
x = 6.022 x 10^23 * 4.5 / 23 = 1.2 x 10^23 atoms Correct option is option A.
Which of these is an extensive ?
A- density
B- melting point
C- temp.
D- volume
How many significant figures does 0.857610 have?
Answer: 6
Explanation:
Because it's 6 after the decimal
Matching
Match the word to the definition. Write the letter on the line.
6. Type Scientfic nquiry
А. This group shows the effect of the variable being tested
7. Type_ Hypothesis
В. This is the one variable that is changed
8. Type Control group
с. A welltested explanation for experimental results
9. Type Experimental group D. The many ways in which scientists study the natural world
10 Type Independent variable E A possible answer to a scientific question
11 Type Dependent variable F This describes an observed pattern in nature
12 Type Scientific theory G This group is left alone and not experimented on
Н This is the veriable that gets measured
13 Type Scientific law
Click to add speaker notes
Answer:
6. Scientific inquiry - D
7. Hypothesis - E
8. Control group - G
9. Experimental group - A
10. Independent variable - B
11. Dependent variable - H
12. Scientific theory - C
13. Scientific law - F
Explanation:
6. Scientific inquiry - D
Scientific inquiry is the study of the explanation for the natural world phenomenon and it requires many scientific steps.
7. Hypothesis - E
A hypothesis is a possible explanation for a phenomenon or problem. It is tested in order to see if true or not.
8. Control group - G
The control group in a scientific experiment is a group of subjects did not get the treatment and left alone.
9. Experimental group - A
The experimental group is another hand group of subjects that gets treatment and shows the effect of the variable being tested.
10. Independent variable - B
Independent variables change or manipulated during an experiment and cause a response from the dependent variable.
11. Dependent variable - H
The dependent variable is a variable that is dependent on independent variables and changes in the independent variable.
12. Scientific theory - C
A well-tested explanation for experimental results with the scientific process.
13. Scientific law - F
This describes an observed pattern in nature
true or false
The atomic number of an element can be used to find the number of protons and neutrons in a neutral atom
1. Measuring instruments, such as rulers and graduated cylinders, are often used in experiments to increase the A clarity of the hypothesis B. testability of the hypothesis C. accuracy of the data sample size of the data 5
Answer:
C. accuracy of the data sample size of the data
Explanation:
Measuring instruments, such as rulers and graduated cylinders, are often used in experiments to increase the accuracy of the data sample size which is usually gotten from the taken reading.
Measuring instruments such as rulers have accurate readings which makes measurements in any form very easy and more accuracy.
2000 km/sec. Convert that to
m/sec.
Answer:
2000 km/sec
1km=1000m
2000×1000
2000,000 m/sec
A substance has a density of 3.56 g/mL and a mass of 5668 g. What is the volume?
Answer:
The answer is
1592.13 mLExplanation:
The volume of a substance when given the density and mass can be found by using the formula
[tex]volume = \frac{mass}{density} [/tex]
From the question
mass of substance = 5668 g
Density = 3.56 g/mL
The volume is
[tex]volume = \frac{5668}{3.56} \\ = 1592.1348314[/tex]
We have the final answer as
1592.13 mLHope this helps you
give an answer to questions 3 will give you 20 point ASSSAAPP
Answer:
Explanation:
1. It is five valence electrons.
2. It is four valence electrons.
3. It is six valence electrons.
4. It is two valence electrons.
I do hope I helped you! :)
Answer:
1. c
2. b
3. a
4.d
Explanation:
How did Edward Teller died?
Answer:
septembar 9 2003
Explanation:
he died in september 9 2003
Answer:
Your answer:
His cause of death was a stroke ( heart attack)
hope this helped you
please mark as the brainliest (ㆁωㆁ)
What is absolute zero? A) The temperature at which the particles of matter are at their lowest energy points. B) The temperature at which the particles of matter are at their highest energy points. C) Other _______________
Answer:
A) The temperature at which the particles of matter are at their lowest energy points.
Explanation:
Absolute temperature refers to the lowest possible temperature. At this state, no heat energy remains in the substance; the energy of the particles are at their lowest energy points.
How many sig figs are in:
0.0058096
9. How many grams of zinc are needed to produce 12 grams of zinc chloride according to the following equation? Y-
Zn + Cl2 --> ZnCl2
12 grams of zinc
O 2.9 grams of zinc
O 11.6 grams of zinc
O 5.8 grams of zinc
Given :
A balanced chemical equation :
[tex]Zn +Cl_2->ZnCl_2[/tex]
To Find :
How many grams of zinc are needed to produce 12 grams of zinc chloride.
Solution :
Moles of [tex]ZnCl_2[/tex] ,
[tex]n=\dfrac{Given \ wt}{Molecular\ Mass}\\\\n =\dfrac{12}{136.30}\ mol\\\\n=0.088\ mol[/tex]
Now, by balanced chemical equation we can say that 1 mol of Zn produce
1 mol of [tex]ZnCl_2[/tex] .
So, 0.088 mol of Zn is required to produced 0.088 mol of [tex]ZnCl_2[/tex] .
[tex]Mass \ required = molecular \ mass \times moles\\\\m = 65.38 \times 0.088\\\\m=5.8 \ gm[/tex]
Therefore, 5.8 grams of zinc is required.
Hence, this is the required solution.
There are 5 areas of chemistry:physical chemistry, organic chemistry, analytical chemistry, biochemistry and inorganic chemistry.identify which of the five area of chemistry best fits the action done by zoe, a chemist. zoe is using an instrument called a spectrophotometer to precisely determine the levels of various chemicals in a sample of drinking water.
If someone could help me I would really appreciate it. Thank you!
Answer:
Analytical chemistry
Explanation:
because in analytical chemistry checks that different chemicals in water,salt etc....
Which is one precaution to take when working with heat and fire?
O Do not use during experiments
O Keep flammables away.
O Avoid touching face and eyes.
O Do not mix chemicals unless told to do so.
Answer:
Keep flammables away
Explanation:
this would avoid anything catching on fire or burning down
Which is classified as an inner transition element?
a) calcium
b) copper
c) fermium
d) helium
How do electrons behave?
49. Carry out the indicated temperature conversions.
40 °C to Fahrenheit degrees
b. -40 °F to Celsius degrees
c. 232 K to Celsius degrees
d. 232 K to Fahrenheit degrees
Answer:
sorry but dorks dont learn maths
Explanation:
just kidding no offense but i think umm 1st one will stay same
i searched google
Which of these features of Earth's crust are caused by the shifting of tectonic plates?
A
mid-ocean ridges
B
desert sand dunes
С
arctic glaciers
D
continental shelves
To solve this we must be knowing each and every concept related to tectonic plates. Therefore, the correct option is option A among all the given options.
What is tectonic plates?The lithosphere, which includes the crust and topmost mantle, is divided into portions by tectonic plates. Numerous dangers, including volcanic eruptions, earthquakes, and tsunamis, are caused by the relative movement of tectonic plates.
Because of the makeup of the rocks inside the plates, tectonic plates can float on the mantle. This reduces their density relative to the mantle. Granite rock, which contains quartz, feldspar, as well as other relatively light materials mostly comprised of silicon and aluminum, makes up the continental crust. Mid-ocean ridges, earth's crust are caused by the shifting of tectonic plates.
Therefore, the correct option is option A.
To know more about tectonic plates, here:
https://brainly.com/question/29773676
#SPJ2
What is the ion symbol for Xenon ?
Answer:
Xe
Explanation:
if ur talking about what it is for xenon
During dialysis, water and urea pass from the blood into the dialysis fluid. Proteins stay in the blood.
(a) Name the process by which water passes from the blood to the dialysis fluid.
(b) Describe the process you have named in (a).
(c) Explain why water passes out of blood but proteins do not.
Answer:
Healthy kidneys clean your blood and remove extra fluid in the form of urine. They also make substances that keep your body healthy. Dialysis replaces some of these functions when your kidneys no longer work. There are two different types of dialysis - hemodialysis and peritoneal dialysis. The following is about hemodialysis.
What is an electrolyte in an electrochemical cell?
Answer:
An electrolytic cell uses electrical energy to drive a non-spontaneous redox reaction. An electrolytic cell is a kind of electrochemical cell. ... The electrolyte is usually a solution of water or other solvents in which ions are dissolved. Molten salts such as sodium chloride are also electrolytes.
Explanation:
Explanation:
An electrolytic cell has three component parts: an electrolyte and two electrodes (a cathode and an anode). The electrolyte is usually a solution of water or other solvents in which ions are dissolved. Molten salts such as sodium chloride are also electrolytes.