Answer:
a pure substance consists only of one element or one compound. a mixture consists of two or more different substances, not chemically joined together.
Explanation:
12. Predict How much of a sample of radioisotope remains after one half-life? After two half-lives?
ANSWER:
3 4 of the original mass has decayed.
EXPLANATION:
After 1 half life, clearly HALF of the original isotope remains. And after TWO half-lives, a HALF + HALF of a HALF, i.e. 3 4 of the original mass has decayed.
Hope This Helped!!
why is it necessary to use clean sponge and cleaning rags in dishwashing?
Answer:
cloths/sponges can harbor harmful pathogens and spread germs if not cleaned frequently. A damp, smelly dish cloth/sponge is telling you germs are multiplying!
Explanation:
hope this is able to help you :)
What most likely happens when a liquid gains heat?
O it changes into gas
it changes into a solid
Onts temperature decreases
O its temperature remains constant
-Jewel Warren
it turns into a gas due to vaporization
Find the molarity of 194.55 g of sugar (c12h22o11) in 250. ml of water.
[Then mother noticed that two children who are watching the game are sick and coughing.She told her son to keep distance from those children to avoid getting sick]
1.Observe illustration no.1 and read the caption.Why did the mother ask her son to avoid the kid with cough?
2.Observe illustration no.2 and read the caption.Why did the mother let her son play with the kid with asthma?
please don't report this
Answer:
in illustration 1
the mother told her son not to play with the boy having cough because it is a transferable disease which could cause him also to get sick and would get cough.
while in
illustration 2
the mother let the boy play with the boy having asthma because it is not a transferable disease which wold not affect him or any one else.
Explanation:
this is the reason
#1
Cough is a infectious disease .It spreads through the droplets falling outwards during coughing.If her son stays there for long time he would be affected by cough also or he would get sick .So the mother denied .#2
Asthama is although a disease of lungs but it doesn't spread through air or droplets.It's not infectious .So nothing would happen if her child playsCan diamond sublime at any pressure up to 1011 kPa? Explain your answer.
Yes, at high temperature and pressure (1011 kpa), diamond can change directly (sublime) into gaseous form.
What is a diamond?Diamond is a solid form of the carbon element with its atoms arranged in a crystal structure called diamond cubic.
Diamond has some interesting properties, which is written below;
Diamond is extremely hard and non volatile substanceDiamond can sublime (change directly to gaseous sate)A diamond interacts with oxygen in the air and disappears to form carbon dioxide.
Thus, at high temperature and pressure (1011 kpa), diamond can change directly (sublime) into gaseous form.
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What is the unbalanced and balanced equation of elephant's toothpaste!? PLEASE HELP!!
Answer:
2 H2O(g) + O2(g)
2 O-1 → O20 + 2 e- 4.
Explanation:
Essentially elephant's toothpaste is just the decomposition of H2O2, hydrogen peroxide. It's catalyzed by KMnO4
Balanced Equation: [tex]2H_2O_2 \ -- > \ 2H_2O \ + \ O_2_[/tex]
Unbalanced Equation: [tex]H_2O_2 \ -- > \ H_2O \ + \ O_2[/tex]
how do energy sources poly a role in the rock formation?
Sun (radiation), winds (eolic) and water (hydraulic) are all sources of energy that work together during rock formation.
What is rock formation?The rock formation is a very slow process that occurs at a geological time, which may take millions of years.
During this period, rocks are shaped by different types of energy, especially radiation and erosion (wind and water bodies)
In conclusion, the sun (radiation), winds (eolic) and water (hydraulic) work together during rock formation.
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How do you think the light would travel if the laser pointer was 1000 meters away?
It is entirely dependent on the laser power (mW). The light's divergence is affected by it.
What exactly is a laser?A laser is a device that produces a powerful beam of coherent monochromatic light by stimulating the emission of photons from excited atoms or molecules.
A laser is generated when electrons in optical materials such as glass, crystal, or gas absorb energy from an electrical current or light.
We can see a 5mW 650 nm laser glowing on a white surface in full darkness from 500 to 1 kilometer away.
As a result of the divergence, the predicted dot 1 km away will be a massive dot with a diameter of 20–30 m30 m and will be exceedingly dark.
As a result, it is entirely dependent on the laser.
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Answer asapppp plssss!!!
consider the sample sds for hydrochloric acid and answer the questions,
what type of environment should the hydrochloric acid be stored in? check all that apply
1.)in a beaker
2.)in a cool, well-ventilated area
3.)in a flask
4.)in a tightly closed container
The safety data sheet is used while working in a laboratory and handling chemicals. According to SDS, hydrochloric acid should be stored in a cool, well-ventilated area. Thus, option 2 is correct.
What is hydrochloric acid?Hydrochloric acid has been defined as a strong acid that is liquid formed by the two elements, hydrogen gas, and chloride. Because of their corrosive nature and high reactivity they are recommended to be stored in dark-colored glass bottles.
They should be stored in a cool and well-ventilated area as they can easily react with other metals, alkalis, oxidizing agents, etc. The reaction results in heat formation and gaseous vapors that are harmful when coming in contact.
Therefore, option 2. hydrochloric acid should be stored in dark and cool places.
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How many grams of carbon dioxide would be produced from the following reaction, if 175 kJ of energy is given off? 2 CO + O2 2 CO2 ΔH = -566 kJ
42.6897 grams of carbon dioxide would be produced from the following reaction, if 175 kJ of energy is given off.
How do we calculate moles?The mole (symbol mol) is the SI base unit of material quantity. The amount of substance in an object or sample is a measure of how many elementary entities of a certain substance are present.
Given chemical reaction is:
[tex]2CO + O_2[/tex] → [tex]2 CO_2[/tex]
From the stoichiometry of the reaction, it is clear that 2 moles of carbon dioxide are produced.
Actual moles will be calculated by using the enthalpy and energy value as:
Actual moles of [tex]CO_2[/tex] = 275kJ × ([tex]\frac{2 mol}{566 kJ}[/tex]) = 0.97 moles.
Grams of carbon dioxide = moles X molar mass of carbon dioxide.
Grams of carbon dioxide = 0.97 X 44.01 g/mol
Grams of carbon dioxide = 42.6897 g
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what are three different ways land is used as a resource
short paragraph about volcano and its features.
why is vanilla extract brown when vanilla ice cream is white?
please be as detailed as possible in your answer
Answer:
Because vanilla Ice cream contains vastly more milk, sugar, etc. Then vanilla extract. It only takes a very small amount in comparison to adding that flavor.
Explanation:
I hope this helps girl
Why is vanilla ice cream white instead of brown?
It is true that Vanilla beans are brown in color and it is interesting that with this brown color ingredient, Vanilla Ice Cream is still white. Well, the vast majority of vanilla flavoring comes in the form of extract. Vanilla beans are very expensive and pure Vanilla has great flavor. When Ice Cream is made, the Vanilla we put in the Ice Cream is very insignificant quantity when compared to the milk powder, sugar, and cream that goes into the Ice Cream. Due to the whipping and procedure of the making, the brown color of Vanilla is lost amongst the huge quantities of other ingredients and we get milky white yummy Vanilla Ice cream
the volume of gas collected when the temperature is 11.0c and the pressure is710.mmHg measures 0.148L. what is the calculated volume of the gas (in mL) at 20.0c and 740.mmHg?
Answer:
The calculated volume of the gas (in mL) at 20.0c and 740.mmHg when volume of gas collected at temperature of 11.0° C and pressure of 710 mmHg measures 0.148L is 78. 1 mL
Explanation:
The combined gas law combines the three gas laws, Boyle's law, Charles's law and Gay- Lussac's law. It states that the ratio of the product of pressure and volume and the absolute temperature of a gas is equal to a constant.
P V ÷ T = K
P1 × V1 ÷ T1 = P2× V2 ÷ T2
Parameters :
P1 = Initial pressure = 710.0 mmHg
V1 = 0. 148 L , converting it to mL = 0.148L × 1000 = 148 mL
T1 = Initial temperature = 11° C
P2 = Final pressure = 740 mmHg
V2 = Final volume in mL
T2 = Final temperature = 20° C
Calculations:
V2 = P1 × V1 × T2 ÷ P2 × T1
V2 = 710 × 148 × 11 ÷ 740 × 20
V2 = 1155880 ÷ 14800
V2 = 78.1 mL
Therefore, the calculated volume is 78.1 mL
balanced symbol equation for the following:
magnesium hydroxide + nitric acid → magnesium nitrate + water
[tex]\text{Mg(OH)}_2 + 2\text{HNO}_3 \rightarrow \text{Mg(NO}_3)_2+ 2\text{H}_2 \text{O}[/tex]
A reaction between an alcohol and an organic acid is classified as.
Answer:
esterification reaction ...........
A 500-gram C6H12O6 solution has a concentration of 300 ppm. How many grams of C6H12O6(s) are in this solution?
Considering the definition of ppm, there are 0.15 grams of C₆H₁₂O₆ in the solution.
What is ppmParts per million (ppm) is a unit of measurement for concentration that refers to the number of units of the substance in each million units of the whole.
In other words, ppm indicates the ratio of the concentration of one substance to the concentration of another, as one unit of solute dissolved in one million units of solvent.
ppm of solid and liquid elements is calculated by weight:
[tex]ppm=\frac{weight of the substance analyzed}{ overall weight} x10^{6}[/tex]
Mass of C₆H₁₂O₆In this case, you know:
ppm= 300weight of the substance analyzed= ?overall weight= 500 gramsReplacing in the definition of ppm:
[tex]300ppm=\frac{weight of the substance analyzed}{500 grams} x10^{6}[/tex]
Solving:
[tex]weight of the substance analyzed=\frac{300 x 500 grams}{10^{6}}[/tex]
weight of the substance analyzed= 0.15 grams
Finally, there are 0.15 grams of C₆H₁₂O₆ in the solution.
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Why have scientists changed their ideas on the model of the atom?
Answer:
Scientists used the model to make predictions. Sometimes the result of the experiments were a surprise and they did not fit with the existing model!
Suppose a particular electron has only two allowed energy levels. How many different wavelength photons (spectral lines) would result from all electron 3 transitions between these levels
Energy levels are the fixed places from the nucleus to the electrons of the atoms. Three possible wavelength photons are possible from the transitional levels.
What are spectral lines?Spectral lines are the dark or light uniform spectrum caused by the surplus or insufficient photons in the atom. They absorb and emit light in a certain frequency range.
Photons are transmitted from one energy level to another level of lower energy, three transitions from levels 1 - 2, 1 - 3, and 2 - 3 are possible.
Therefore, 3 spectral lines are possible.
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For the reaction: P4 + 6C12 – 4 PC13
What mass of PCl3 forms in the reaction of 75.0 g P4 with 275 g Cl2?
Answer:
332.3g
Explanation:
hope this helps loves x
seriously what do i put in the x and y table im stuck and need to move to the next assignment
Remember the relationship
P is indirectly proportional to VSo
The pairs are
(2,4)(1,8)(4,2)(12,2/3)(2/3,12)And so on
For your experiment in part B, which factors would you keep constant?
Heating Different Amounts of a Substance
how many moles of O2 will react with 0.6482 moles of H2O?
2C3H6O + 5O2 → 6CO + 6H2O
Answer:
n=0.648 moles
the ratio 5:6
x:0.648
x=0.54 moles
Can someone help me?
Answer: 0.160 M
Explanation:
4. At least one carbon-carbon bond in an alkyne is a triple covalent bond. Other bonds may be single or double carbon-carbon bonds and carbon-hydrogen bonds.
Answer:
hope it helps cuz i did not really understand
159
Which type of reaction is:
4 (NH4)3PO4 + 3 Pb(NO3)4 - 12 NH4NO3 + Pb3(PO4)4
Synthesis
Decomposition
Double Displacement
Single Displacement
Devices that use a liquid spray to remove pollutants from the air are called __________. A) alloys B) particulates C) scrubbers D) minerals E) chlorofluorocarbons (CFCs)
Devices that use a liquid spray to remove pollutants from the air are called scrubbers. The correct option is C.
What is a wet scrubber?Wet scrubber is a pollution removing technique from the air. It is a sprayer which trap the harmful gas molecules from the air.
It is used in factories and industrial exhaust steams.
Thus, the correct option is C. scrubbers.
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PLEASE HELP I NEED ANSWER ASAP
Mark the oxidation nos
Co=0Cu=2+Then
Co=2+Cu=0Gain of electron is reduction
Copper is reduced .
Option D
what mass of Al w(molar mass 78g/mol) would have to be descomposed to produce 100 grams of Al203
Answer:
57.4 g
Explanation:
30.4 g Al will produce 57.4 g Al 2 O 3 30.4 g O 2 will produce 64.6 g Al
2 O 3 .The limiting reagent is aluminum, and the maximum amount of aluminum oxide that can be produced in this reaction is 57.4 g
