The amount remaining at the end of 5 half-lives is 7.81×10¹³ g
From the question given above, the following data were obtained:
Half-life (t½) = 5730 yearsOriginal amount (N₀) = 2.5×10¹⁵ gNumber of half-lives (n) = 5Amount remaining (N) =?The amount remaining can be obtained as follow:
N = 1/2ⁿ × N₀
N = 1/2⁵ × 2.5×10¹⁵
N = 1/32 × 2.5×10¹⁵
N = 0.03125 × 2.5×10¹⁵
N = 7.81×10¹³ g
Therefore, the amount remaining after 5 half-lives is 7.81×10¹³ g
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(iii) Give two reasons why the electrolyte contains cryolite
Answer:
The mixture of cryolite and aluminum oxide has a lower melting point than pure aluminum oxide. This means a lower amount of energy is required to establish effective conditions for electrolysis and thus makes it more cost effective.
Explanation:
mass of 0.5 moles of co2
Answer:
Mass of 0.5 moles of CO2 is 22 gm.
Explanation:
1 mole of CO2 = 44 gm
0.5 mole of CO2 = 0.5 × 44 = 22 gm
25.0g of iron is heated to 100.0 and then placed in 50.0 g of water in a insulated calorimeter. the initial temperature of the water is 38.00. the specific heat of water is 4.181j/g and the specific heat if iron is 0.45j/g. what is the final temp of the water and the iron?
Answer:
Approximately [tex]41.2\; {\rm ^{\circ} C}[/tex].
Explanation:
Let [tex]t\; {\rm ^{\circ} C}[/tex] be the final temperature of the water and the iron.
Temperature of the water would be increase by [tex](t - 38.00)\; {\rm ^{\circ} C}[/tex].
Temperature of the iron would be reduced by [tex](100.0 - t)\; {\rm ^{\circ} C}[/tex].
Let [tex]c[/tex] denote the specific heat of each material. Let [tex]m[/tex] denote the mass of the material. For a temperature change of [tex]\Delta t[/tex], the energy change involved would be:
[tex]Q = c\, m \, \Delta t[/tex].
The energy that the water need to absorb would be:
[tex]\begin{aligned}& Q(\text{water, absorbed}) \\ =\; & c(\text{water}) \, m(\text{water})\, \Delta t (\text{water}) \\ =\; & 4.181\; {\rm J \cdot g^{-1} \cdot K^{-1}} \times 50\; {\rm g} \times (t - 38.00)\; {\rm ^{\circ} C} \\ =\; & (209.05\, t - 7943.9)\; {\rm J} \end{aligned}[/tex].
The energy that the iron would need to release would be:
[tex]\begin{aligned}& Q(\text{iron, released}) \\ =\; & c(\text{iron}) \, m(\text{iron})\, \Delta t (\text{iron}) \\ =\; & 0.45\; {\rm J \cdot g^{-1} \cdot K^{-1}} \times 25.0\; {\rm g} \times (100.0 - t)\; {\rm ^{\circ} C} \\ =\; & (1125 - 11.25 \, t)\; {\rm J} \end{aligned}[/tex].
Since this calorimeter is insulated, the energy that the iron had released would be equal to the energy that the water had absorbed:
[tex]Q(\text{water, absorbed}) = Q(\text{iron, released})[/tex].
[tex]209.05\, t - 7943.9 = 1125 - 11.25\, t[/tex].
[tex]t \approx 41.2[/tex].
Thus, the final temperature of the water and the iron would be approximately [tex]41.2\; {\rm ^{\circ} C}[/tex].
A student is trying to classify an unidentified, solid gray material as a metal or a nonmetal. Which question will best help the student classify the material?.
The question that will best help the student to classify the material is; "is the material malleable or ductile?"
Generally, materials can be classified as metals or non metals. There are properties that are particular to metals and there are properties that are particular to nonmetals and these properties can be used to identify each one of the materials.
The question that will best help the student to classify the material is; "is the material malleable or ductile?" These metallic properties.
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Missing parts;
A student is trying to classify an unidentified, solid gray material as a metal or a nonmetal. Which question will best help the student classify the material? A. Is the material malleable or ductile? B. Does the material feel hard to the touch? C. Will the material float in water? D. Does the material feel rough or smooth?
Which two observations are evidence that a chemical change is happening?
A. A yellow liquid forms as a yellow solid is slowly heated.
I B. Bubbles of gas are released when a solid is combined with a
liquid.
I c. Solid crystals form as the temperature of a liquid is lowered.
D. Light and heat are given off after a spark ignites a substance,
______= Speed / Wavelength
Answer:
Frequency
Explanation:
It’s kinda self-explanatory but bascially speed=wavelength times frequency
Answer:
Frequency is Speed divided by Wavelength
Step-by-step explanation:
Don't think there needs to be an explanation for the formula, unless you want the conceptual understanding
Different isotopes of an element have different numbers of:
Explanation:
Different isotopes of an element have different numbers of mass number
What role does each type of chemical play in the firework
Answer: Antimony: Antimony is used to create firework glitter effects. Barium: Barium is used to create green colors in fireworks,
Explanation:
Answer:
Explanation:Antimony: Antimony is used to create firework glitter effects. Barium: Barium is used to create green colors in fireworks,
Helpp you will get a brainly
HC= Hydrocarbon
CH=benzene
Explanation:
HC is Hydrocarbon, how? -- Hydrocarbon, a category of substances consisting only of hydrogen and carbon.
CH is benzene, how? -- benzene is represented by the empirical formula CH, which indicates that a typical sample of the compound contains one atom of carbon (C) to one atom of hydrogen (H).
----(Is this what you meant???)
Helppp plzzzz!!!!!!1Asappppp
Answer:
0.178M
Explanation:
The question can immediately be understood as comparing two states.
- The initial state M1 , V1.
- The Final state M2 , V2.
M - Molarity.
V - Volume (in mili liters/ml/ in this case).
The formula is stated as:
M1 * V1 = M2 * V2
Given- Required
M1 = 0.125M V1 = 265ml M2 = ?
V2 = 186ml
Plug these values into the formula above and divide V2 to get M2.rearranged formula - M2 = M1 * V1 / V2 = 0.125M * 265ml / 186ml
= 0.178091397 M ~ ~ 0.178M.
Write the charges for each part of this equation.
Answer:
the Aluminium Al have +3 charges and idion have I) have - 2 charges
Select the correct answer. In which situation is chemical energy being converted to another form of energy? A. a lamp plugged into the electric grid B. a fluttering flag C. a floating wooden log D. a burning candle
Answer:
D. A burning candle. (chemical energy into energy of heat and light, i.e. thermal and wave)
Explanation:
comment and tell me if it right.
The situation in which chemical energy being converted to another form of energy is a burning candle.
So, option D is correct one.
What is chemical energy?The energy produce by the chemical reaction is called chemical energy.
Example: burning of candle.
Give the example of energy conversion.When lamp plugged into electric grid then electrical energy is converted into light energy.When candle is burn then chemical energy is converted into light energy.No energy takes place during a fluttering flag and a floating wooden log.learn more about chemical energy,
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Is mercury an electrolyte at room temperature?
Answer:
No
Explanation:
Despite mercury being a metal, it is a liquid at room temperature. It cannot be an electrolyte. This is because most of the liquids that can conduct electricity or acids bases and salts whereas mercury is a metal.
how much usable energy is extracted from one glucose molecule
We can extract 3×3 power 3 from glucose molecules
How many moles is 2.50 grams of oxygen?
Answer:
Mole is a number that connects mass of a substance with its number of particles. 2500 g of O2 = 1/32 x 2500 = 78.125 moles
Explanation:
have a great day
PLEASE HELP!!
Explain the physical and chemical properties of water, including its different phase changes. Why is water so critical for human life?
Submission
how can knowledge of percent composition help you as a consumer ? how can you promote responsible consumerism ?
Answer:
it is a nice question....my mind tells me that the first is it use me as a good vibes and can use to anything the second i will do my best too absorbe it.
Explanation:
Hope this help...
How can one determine if a compound is ionic or covalent?
Answer:
If a compound is made from a metal and a non-metal, its bonding will be ionic. If a compound is made from two non-metals, its bonding will be covalent.
In a physical change, the makeup of matter is changed.
True or false?
Answer:
false
Explanation:
because it's just a physical change, the matter won't be changed.
Hope this might help you! I don't know if this is going to be right on everything, but it's a anwser
In a physical change, the makeup of matter is changed. This statement is false.
What do you mean by the term physical change ?
A physical change occurs when a substance experiences a change in its physical characteristics. A physical alteration may usually be reversed. No new material is produced with such a transformation.
As the substance's composition changes, a chemical reaction takes place. A chemical change happens when bonds are broken and new ones are created.
Physical change is a sort of change when the substance's chemical makeup does not change. Often, this type of alteration entails a change in the substance's size, form, and condition.
Thus, In a physical change, the makeup of matter is not changed because it's a physical change.
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A group of students were asked to design a device that converts light energy into heat. They built a small solar oven using a tin can and aluminum foil. The device reflects light into the can, warming up its contents.
Which action would most improve the design of the solar oven?
O A. Add a mirror to reflect light away from the can.
O B. Use hand lenses to focus the light into the can.
O c. Add a fan to make sure the food is evenly warmed.
O D. Change the tin can to a box with a lid to Increase cooking space.
Answer:
answer is b
Explanation:
I think it is b. I don't know what land lenses are but focusing light on the can would heat it up more.
pls help :)))))))pop
Answer:
c-a-b
Explanation:
HELP PLSS ASAP PLEASE
Answer:
5.24 x 10^23
Explanation:
Avogadro's constant is 6.02 x 10^23
1 mol = 6.02 x 10^23
0.87 mol = 6.02 x 10^23 x 0.87 = 5.24 x 10^23 (2.d.p)
Mercury is an environmental pollutant that is produced by the burning of
fossil fuels and can be toxic to wildlife and humans. What does this show
about the impact of chemicals on the environment?
A. The harm chemicals could have on the environment outweighs the
benefits that people get from the chemicals.
B. People cannot control the negative effects of chemicals on the
environment.
C. All chemicals that people introduce into the environment are
harmful.
D. The beneficial effects people get from chemicals may have
unintended harmful effects on the environment,
XTRA POINTS 4 CHRISTMAS
What is an empirical formula?
Explanation:
a formula giving the proportions of the elements present in a compound but not the actual numbers or arrangement of atoms.
Answer:
The answer is A
Explanation:
its is the chemical formula in which the subscripts are given in the smallest ratio
how does the number of valence electrons change as you move to the right across the periodic table?
Answer:
The number of valence electrons goes up by one each time you move
report the elements half life. if we start with 100g of your element (platinum) how long will it take to have 6.26g?
Answer:
did u get the answer yet
Explanation:
The amount of energy involved when an electron is acquired by a neutral gaseous atom is what?
why do you think polar aprotic solvents increase the rate of an sn2 reaction
Students in Mr. Garcia's class were having a race! No, not running. Instead they rolled tennis balls down a wooden track. The tennis balls have the same mass and diameter. Using the data table, decide which ball had the MOST kinetic energy.
Answer:
it's entertaining. Energy though is the answer
How many atoms are in 11.5g of Hg