Answer:
I guess eraser is better than bread crumbs
Erasers would be better than white bread or crumbs to erase the pencil marks because they would not leave any food marks on the paper and using bread crumbs.
What is an eraser?An eraser is an object of stationary which is used to remove pencil marks from the paper. It is used during writing, when we write something wrong, we could erase or remove the writing from the paper. It is very useful for small children because they usually make mistakes while studying.
Erasers are made from the milk of rubber plants. The milk is collected from the plants, and then it is mixed with chemicals and set down, and then cut into pieces.
Thus, Erasers would be preferable to utilizing bread crumbs or white bread because they would not leave any food stains on the paper after erasing the pencil markings.
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everyday problems related chemistry
MAINLY CONCENTRATED IN THE INDUSTRY.
Answer:
Compounds such as Sulphuric acid and Nitric acid present in polluted air and come into contact with rain water and form acid rain.
Explanation:
Fossil fuels contain such compounds like nitrogen sulphur in addition to carbon. Due to combustion of these fuels,large amount of sulphur dioxide and other compounds are discharged into atmosphere.these oxides dissolve in rain water forming mineral acids.
Convert 84 miles to kilometers (there are 0.6 miles in a kilometer)
using the method dimensional analysis
Answer:
Explanation:
Put the given unit on the bottom of the brackets.
84 miles [tex]\frac{1 km}{0.6 miles}[/tex] = 84/0.6 = 140 km
2 Figure 3.1 shows two different forms of carbon, A and B.
A
B
Figure 3.1
a Name the two forms of carbon shown.
Answer:
show the pictures pls specify
Which of the following has maximum number of atoms?
(a) 18 g of H2O
(b) 18 g of O2
(c) 18 g of CO2
(d) 18 g of CO4
Answer:
(a) 18 g of H2O
Explanation:
The molecule with great number of moles will have great number of atoms.
By observation, since all compounds have same mass, water has the least molcular mass
[tex]H_{2} O = \: 18 \: g[/tex]
Answer:
18g of H2O
Explanation:
the molecule with great number of moles will have great number of atoms .
(a) option is correct
Which state of matter has particles that vibrate and can change place but remain touching in a random arrangement.
A. Liquid
B. None of these
C. Plasma
D. Gas
The particles in the solid are touching with very little space between them. The particles in a liquid usually are still touching but there are some spaces between them. The gas particles have big distances between them.
...
Liquids Solids and Gases:
NON OF THESE
URGENT PLEASE ELPP!!!Calculate the density of a piece of metal that has a mass of 2.5 × 102 kg and a volume of 4.1 × 103 m3.
Answer:
Density =mass/Volume
First of all let's find the mass
= 2.5 ×102kg
= 225kg
Then the volume
=4.1 × 103 m3
=422.3m3
225kg /422.3m3
=0.53279659
The density of a piece of metal that has a mass of 2.5 × 102 kg and a volume of 4.1 × 103 m3 will be 6.03 kg/m³ .
What do you mean by the density of a substance ?
Density is defined as the ratio of mass of the object to the volume of the object. Different substances have different densities.
The mathematical expression for density is as follows:
Density=Mass/Volume
The mass of a substance is expressed in kilograms and the volume is expressed in liter.
Thus, the unit of density is kg L⁻¹.
The density of a substance does not depend on the amount of the matter.
Thus, density is an intensive property.
To calculate the density -:
Given,
Mass= 2.5 ×102 kg=2550 kg
Volume=4.1 × 103 m³=422.3m³
Density=mass/volume
Density=2550/422.3
Density=6.03kg/m³
Hence, 6.03kg/m³ is the density of a piece of metal .
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Which among the following mixtures will show tyndal effect?
i) copper sulphate solution
ii) sand in water.
iii) milk.
iv) starch solution
Answer:
milk and starch solution are the colloids, hence these will show the tyndall effect
Answer:
milk and starch solution
Explanation:
Tyndall effect is shown by colloidal solutions. It is not shown by true solutions or suspensions.
Milk and starch solution are colloidal solutions. They show tyndall effect. On the other hand, common salt and copper sulphate solution are true solutions. They do not show tyndall effect.
A mixture of liquids having almost the same boiling point cannot be separated by simple distillation?Why?
Answer:
Distillation:
Distillation is the process in which two or more liquids are separated on the basis of their boiling points.
Process:
Liquid mixture is heated. The liquid which is of low boiling point evaporates first and is condensed separately. This is followed by the liquid having more boiling point than the previous one and so on.
Reason:
A mixture of liquids having almost same boiling points cannot be separated. This is because both the liquids will evaporate at almost the same time when heated and thus, we will obtain the same liquid mixture again. No separation will occur.
[tex]\rule[225]{225}{2}[/tex]
Hope this helped!
~AH1807Peace!what the recipe of momo
Answer:
Down is the recipe for momo..
Explanation:
recipe..
. Sieve the wheat flour carefully to remove lumps.
. Add water and knead the flour well to prepare a dough
. Remove the skin of the boiled potato ,cut into small pieces
. Heat the cooking oil in frying pan, and fry the pieces of onions cabbage green chili tomato pea etc.
. Prepare a mix veg stuffing by mixing potato other vegetables , green coriander and salt.
. Prepare a small balls of dough and roll it out of belna.
. Put 10 gm of mix vegetables stuff in the center of rolled dough and close it from all the sides to make a small ball.
. steam the momo for 10-15 minutes. After that it will be ready to serve.
. A sauce or pickle is usually eaten with momo.
Answer:
Explanation:
Sieve the wheat flour carefully to remove lumps.
b. What chemist finds
out how much nitrogen is in a sample of air
9. What is useful in constructing scientific questions, methods, and explanations?
A. formaldehyde
B. a large research team
C. a very limited amount of time
D. creativity
Answer: C
creativity
Explanation:
C. Because the results of some experiments might not be explained by any
known theories.
Answer:
creativity
Explanation:
MgCl2(at)+Br2(l)=MgBr2(at)+Cl2(g)
how do you write in a word equation
aqueous Magnesium Chloride reacts with liquid Bromide to form aqueous Magnesium Bromide and Chlorine gas
Magicians often use ‘flash powder’ in their acts. Flash powder contains 69.0% potassium chlorate (31.9% K, 28.9% Cl, 39.2% O) and the remainder is aluminium. Calculate the percentage composition by mass of each element in flash powder
Answer:
[tex]\rm K[/tex]: approximately [tex]22.0\%[/tex].
[tex]\rm Cl[/tex]: approximately [tex]19.9\%[/tex].
[tex]\rm O[/tex]: approximately [tex]27.0\%[/tex].
[tex]\rm Al[/tex]: [tex]31.0\%[/tex].
Explanation:
Consider a [tex]100\; \rm g[/tex] sample. There would be [tex]69.0\% \times 100\; \rm g = 69.0\; \rm g[/tex] of [tex]\rm KClO_{3}[/tex] and [tex]100.0\; \rm g - 69.0\; \rm g = 31.0\; \rm g[/tex] of [tex]\rm Al[/tex].
Out of that [tex]69.0\; \rm g[/tex] of [tex]\rm KClO_{3}[/tex]:
[tex]31.9\%[/tex] (by mass) would be [tex]\rm K[/tex]: [tex]31.9\% \times 69.0\; \rm g \approx 22.0\; \rm g[/tex].
[tex]28.9\%[/tex] (by mass) would be [tex]\rm Cl[/tex]: [tex]28.9\% \times 69.0\; \rm g \approx 19.9\; \rm g[/tex].
[tex]39.2\%[/tex] (by mass) would be [tex]\rm O[/tex]: [tex]39.2\% \times 69.0\; \rm g \approx 27.0\; \rm g[/tex].
Overall, the composition (by mass) of each element in this mixture would be:
[tex]\rm K[/tex]:
[tex]\begin{aligned} & \frac{31.9\% \times 69.0\; \rm g}{100\; \rm g} \\ =\; & 31.9\% \times 69.0\% \\ \approx \; & 22.0\%\end{aligned}[/tex].
[tex]\rm Cl[/tex]:
[tex]\begin{aligned} & \frac{28.9\% \times 69.0\; \rm g}{100\; \rm g} \\ =\; & 28.9\% \times 69.0\% \\ \approx \; & 19.9\%\end{aligned}[/tex].
[tex]\rm O[/tex]:
[tex]\begin{aligned} & \frac{39.2\% \times 69.0\; \rm g}{100\; \rm g} \\ =\; & 39.2\% \times 69.0\% \\ \approx \; & 27.0\%\end{aligned}[/tex].
[tex]\rm Al[/tex]:
[tex]\begin{aligned}& \frac{100\; \rm g - 69.0\; \rm g}{100\; \rm g} \\ =\; & 100\% - 69.0\% \\ =\; & 31.0\%\end{aligned}[/tex].
please help ASAP please!!
Answer:
If I am correct the last one because the pressure is decreasing and the temperature is increasing
a sample of element X contains 90% X-35 atoms,8.0%X-37 atoms, and 2.0% X-38 atoms. The average atomic mass will be closest to which value?
Answer:
35.2.
Explanation
R.A.M= Mass of isotopes divide by 100 percent
in h-atom if x is radius of first bohrs orbit de broglie wavelength of an atom in 3rd orbit is a.3πx b.6πx c.9x/2 d.x/2
please I need complete explanation fast
Answer:
can you type question properly.
What's the volume of one mole of an ideal gas at Standard Temperature and Pressure? Question 17 options: A) 11.2 L B) 22.4 L C) 33.4 L D) 12.2 L
Answer:
=zero degrease, 1 atm)? so the volume of an ideal gas is 22.l/mol at STP this, 22l.4Lis probably the most remembered and least useful number in chemistry
Answer:
B) 22.4
Explanation:
Think of a real life simple problem and apply scientific method to solve the problem given to the guide questions.
Scientific Approach is to identify a problem and finding solution to the problem. There are various steps in scientific approach to solve a problem,
Identify the problem
Analyze the impact
Find available solution
Evaluate different alternative solutions
Choose the best alternative
Apply the solution to the problem
Measure the results
Lets say there is a fire at some place.
There are various solution available, the fire can be slowed down by water, using fire extinguisher or sand.
The best alternative is to use fire extinguisher.
The fire is vanished after the use of fire extinguisher.
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how many atoms of gold are present in 0.6 gm of 18 caral gold? ( 24 caral gold in 100% pure) atomic weight of gold = 197?
Answer:
HERE'S YOUR ANSWERWe are given that the ring is made up of 20 carrat gold. 20 carrat gold means 20 parts of gold and 4 parts of other metal (usually copper or silver). Thus, the percentage of gold in 20 carrat gold will be
= (20 / 24) X 100
= 83.333 %
We can now calculate the mass of gold in the ring. We are given that the ring weighs 300 mg. So, the mass of gold in ring will be
= (83.333 / 100) X 300
= 250 mg
Thus, the mass of gold in 300 mg of the ring is 250 mg.
Now the molar mass of gold is 197 g. This means that there are 6.023 X 1023 atoms of gold in 197g of gold. Thus
197g of gold = 6.023 X 1023 atoms of gold
1g of gold = (6.023 X 1023 ) / 197 atoms of gold
250 mg or 0.25g of gold = (6.023 X 1023 X 0.25) / 197 atoms of gold
= 7.643 X 1020 atoms of gold
HOPE IT HELPS MAN ☺️What is known about a reaction with a negative enthalpy?
A. The reaction is endothermic,
B. The reaction is spontaneous,
C. The reaction is exothermic,
D. The reverse reaction is favored,
Considering the definition of enthalpy of reaction, the correct answer is option C. a reaction with a negative enthalpy indicates that the reaction is exothermic.
Definition of enthalpy of reactionThe enthalpy of a chemical reaction as the heat absorbed or released when chemicals are transformed into a chemical reaction and it occurs at constant pressure.
The enthalpy is an extensive property, that is, it depends on the amount of matter present.
Finally, it must be taken into account that:
A reaction is called exothermic if its enthalpy of reaction is negative (that is, if the system gives up heat).A reaction is called endothermic if its enthalpy of reaction is positive (that is, if the system absorbs heat).SummaryIn summary, a reaction with a negative enthalpy indicates that the reaction is exothermic.
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What really causes fire to burn?
Explanation:
Heat, Oxygen and Fuel
hope it helps u
Answer:
a friction helps to cause fire and oxygen helps to increase it
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Balance the following equations
ANSWER
2Ba + 2HBr → 2BaBr + H2
2BiCl3 + 3H2S → Bi2S3 + 6HCl
Br2 + 2KI → I2 + 2KBr
4Fe + 3O2 → 2Fe2O3
I HOPE THIS WILL HELP YOU IF NOT THEN SORRY HAVE A GREAT DAY:)Answer:
[tex]3Mg _{(s)} + N _{2(g)} → Mg_{3} N _{2(s)}[/tex]
[tex]Ba _{(s)} + 2HBr_{(g)} → BaBr _{2(s)} + H _{2(g)}[/tex]
[tex]2BiCl_{3(s)} + 3H_{2} S _{(g)} → Bi _{2} S _{ 3(g)} + 6HCl _{(g)} \\ [/tex]
[tex]Br_{2(g)} + 2KI _{(g)} → I _{2(g)} +2 KBr _{(g)}[/tex]
[tex]4Fe_{(s)}+ 3O_{2(g)} → 2Fe_{2} O _{3(s)} [/tex]
What would you need to do to calculate the molality of 10 g of NaCl in 2 kg of
water?
A. Convert the 2 kg of water to liters of water.
O B. Convert the 10 g of NaCl to moles of NaCl.
C. Convert the 2 kg of water to moles of water.
O D. Convert the 10 g of NaCl to kg of NaCl.
Answer:
O B. Convert the 10 g of NaCl to moles of NaCl.
Explanation:
The formula for finding the molality is m=moles of solute/kg of solvent. The solute for this question is NaCl and the solvent is water.
(10g NaCl)(1 mol NaCl/58.44g NaCl)=0.1711 mol NaCl
58.44 is the molar mass of NaCl
m=0.1711 mol NaCl/2 kg H2O
m=0.085557837
the smell spreads immediately after you burn agarbatti in this example what is your condition about intermolecular force
Answer:
The aroma of agarbatti spreads quickly once you burn it because the particles in the agarbatti move endlessly in all directions. Both, the air and aroma, have large intermolecular forces which is why the molecules of air scatter immediately once agarbatti is burned.
why is m3 is derived unit?
Answer and Explanation:
There are 7 base units, m is one of them. Any unit made up of a combination of them is a derived unit. Also, any unit that is defined to be equivalent to a combination of base units is a derived unit.
how many moles of sodium are produced in 46g of substance?
Answer:
Only 2moles are produced from it
26. Which of the following Is a reason that Venus is not ideal for supporting life?
• It lacks an atmosphere allowing for frequent meteorite collisions.
It
has a thick atmosphere which causes extremely high temperatures.
It has the perfect amount of atmosphere, but not enough hydrogen.
It
has a thin atmosphere which prevents llquid water from
existing on the planet surface.
Answer:
It has a thick atmosphere which causes extremely high temperatures.
Explanation:
What can form as a result of a chemical reaction?
Answer:
O. compounds
Explanation:
[tex]{ \underline{ \sf{ \blue{christ \: † \: alone}}}}[/tex]
please answer
√In the morning, when the sun rises in the east, your shadow will be seen on the
•East
•West
•North
•South
√From which part of plant cotton and jute obtained
Answer:
hi
Explanation:
1 east
2 the flower bud for cotton and for jute the leaves
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A precipitation reaction 2. A Lewis acid-base reaction the produces a coordination complex: A Lewis acid-base reaction the produces a coordination complex 3. An oxidation-reduction reaction that is also a synthesis reaction: An oxidation-reduction reaction that is also a synthesis reaction Column B a. Pb2 (aq0 CrO42-(aq) --> PbCrO4(s) b. 2 Mg(s) O2(g) -> 2 MgO(s) c. Ag (aq) 2NH3(aq) --> [Ag(NH3)2] (aq)
Answer:
Pb2+ (aq) + CrO42-(aq) --> PbCrO4(s) - A precipitation reaction
2 Mg(s) + O2(g) -> 2 MgO(s) - An oxidation-reduction reaction that is also a synthesis reaction
Ag^+ (aq) + 2NH3(aq) --> [Ag(NH3)2]^+ (aq) - A Lewis acid-base reaction the produces a coordination complex
Explanation:
A precipitation reaction is one in which two aqueous reactants yields an insoluble product called a precipitate as shown in reaction 1 above.
In the second reaction Mg is oxidized from zero to + 2 while oxygen was reduced from zero to -2 as the MgO is formed hence the reaction is an oxidation-reduction reaction that is also a synthesis reaction.
In the third reaction, Ag^+ a Lewis acid reacts with NH3, a lewis base to yield the complex [Ag(NH3)2]^+.
