Answer:
D.) The characteristics of the mixture change within a sample
Explanation:
Because the guy above me is wrong
Answer:
D.) The characteristics of the mixture change within a sample.
Explanation:
HTH!! Have a good day!!! Don't forget to smile!!!!
Which of the following presents a safety hazard while working in the science laboratory?
A knowing how to use equipment
B wearing safety goggles
C following directions
D working alone
Answer:
D working alone
Explanation:
Working alone is the only option that could potentially be a safety hazard; if you have no one watching your back, errors could occur, like dropping glass or burning your hand, and no one is around to help you.
Choices A, B, and C are not correct because those are all good safety standards.
Need help with these three pls!!!!!
How many joules are produced when 45 gram of copper is placed into water that releases them temperature from 12c to 71c (c)=0.75j/g*c
Answer:
Heat energy (Q) = 1.9925 KJ = 2 KJ (Approx)
Explanation:
Given:
Mass of copper (M) = 45 gram
Change in temperature (ΔT) = 71°C - 12°C = 59°C
Specific heat (c) =0.75 j /g*c
Find:
Heat energy (Q) = ?
Computation:
Heat energy (Q) = Mass(M) × Change in temperature (ΔT) × Specific heat (c)
Heat energy (Q) = 45 gram × 59°C × 0.75 j /g*c
Heat energy (Q) = 1991.25 J
Heat energy (Q) = 1.9925 KJ = 2 KJ (Approx)
Relate dark matter to the development of the universe after the Big Bang. In 3-5 sentences, speculate on how the development of the universe would have been different if there had been no dark matter. In your answer, use the term structures.
Please answer this and ill mark you as brainliest
Answer:
Dark matter also called baronic matter is the matter that makes up 27% of the universe.
In 1933 it was determined as that mass that cannot be seen, that is, the non-visible mass of outer space.
Dark matter also plays a central role in the formation of structures and the evolution of galaxies and has measurable effects on the anisotropy of cosmic microwave background radiation. The composition of this matter is unknown today.
The dark matter component has considerably more mass than the "visible" component of the Universe.
Explanation:
There are certain researchers who say that the appearance of dark matter was before the appearance of the big bang.
A relevant fact of this matter is that dark matter exerts gravity, and that gravity affects the movements of objects.
Despite the fact that nothing is known about its origin, astronomers have amply demonstrated that dark matter plays a determining role in the formation of galaxies and galactic clusters, which could not maintain their cohesion without its existence, but many doubt that it is the remainder / remnant or product of a big bang.
I AM GIVING BRAINLIEST PLEASEE HELPPPP I NEED HELPPPPPP PLEAEEEEEE
63.2 g of BaCl 2 are dissolved in enough water to make a 634 mL solution. What is the molarity?
Answer:
0.479 M or mol/L
Explanation:
So Molarity is moles/litres of solution...often written as M=mol/L
So here we are given grams of BaCl2 which we have to convert to moles. To convert to moles of BaCl2 we have to divide 63.2 g BaCl2 by molar mass of BaCl2 which is 208.23 g/mol so you get 63.2/208.23 = 0.3035 moles of BaCl2
Second step is converting the 634mL to litres by simply dividing by 1000 because we know 1 litre has 1000ml so 634/1000 = 0.634L
Now we just plug these guys in our molarity formula M=mol/L
M= 0.3035/0.634 = 0.479 M or mol/L
Answer:
Interestingly enough, I'm not getting
0.0341% w/v
either. Here's why.
Start by calculating the percent composition of chlorine,
Cl
, in calcium chloride, This will help you calculate the mass of chloride anions,
Cl
−
, present in your sample.
To do that, use the molar mass of calcium chloride, the molar mass of elemental chlorine, and the fact that
1
mole of calcium chloride contains
2
moles of chlorine atoms.
2
×
35.453
g mol
−
1
110.98
g mol
−
1
⋅
100
%
=
63.89% Cl
This means that for every
100 g
of calcium chloride, you get
63.89 g
of chlorine.
As you know, the mass of an ion is approximately equal to the mass of the neutral atom, so you can say that for every
100 g
of calcium chloride, you get
63.89 g
of chloride anions,
Cl
−
.
This implies that your sample contains
0.543
g CaCl
2
⋅
63.89 g Cl
−
100
g CaCl
2
=
0.3469 g Cl
−
Now, in order to find the mass by volume percent concentration of chloride anions in the resulting solution, you must determine the mass of chloride anions present in
100 mL
of this solution.
Since you know that
500 mL
of solution contain
0.3469 g
of chloride anions, you can say that
100 mL
of solution will contain
100
mL solution
⋅
0.3469 g Cl
−
500
mL solution
=
0.06938 g Cl
−
Therefore, you can say that the mass by volume percent concentration of chloride anions will be
% m/v = 0.069% Cl
−
−−−−−−−−−−−−−−−−−−−
I'll leave the answer rounded to two sig figs, but keep in mind that you have one significant figure for the volume of the solution.
.
Explanation:
How are electrons similar and different to the planet Earth?
Answer:
The planets themselves are composed of several trillions or quadrillions or more atoms. As far as hard science is concerned, it would be really hard to picture them as electrons. Conclusion: It can be said with a great accuracy that our planets are NOT huge electrons.
Rutherford's experiments showed that the mass of atoms was mostly concentrated in a very small region, with charge equal to the atomic number- the nucleus. He absolutely did not show, nor is it true, that electrons orbit the nucleus as if they were planets. That was a guess people made in trying to figure out how to picture the atom.
(Hope this helps) Sky
A community includes
A. all of the living organisms in a specific place at a specific time,
B. all plants, animals, minerals, and water in a specific place at a specific time,
C. only the plants in a specific place at a specific time.
D. only the animals in a specific place at a specific time.
Answer:
answer: A. all of the living organisms in a specific place at a specific time
Explanation:
aight imma let you guys i
Answer:
b
Explanation:
it is right
Why is soap mixed with water?
O A. The soap turns the water molecules into a nonpolar solvent.
B. It covalently bonds to the water so it can be washed away.
O C. Its polar end mixes with the water so it can be washed away.
D. The soap becomes chemically active when mixed with water.
Answer:
Explanation:
Soap breaks up the oil into smaller drops, which can mix with the water. It works because soap is made up of molecules with two very different ends. One end of soap molecules love water - they are hydrophilic. The other end of soap molecues hate water - they are hydrophobic.
Answer:
C. Its polar end mixes with the water so it can be washed away.
Explanation:
Just took test
Which equilibrium describes a reversible reaction a short time after starting the reaction with reactants only?
Answer:
Should be A
Explanation:
What is the correct answer? Please
Answer:
c
Explanation:
how many Atoms of chlorine Cl are there in 3.45 mol Cl?
Answer:
2.078x10^24
Explanation:
No. of atoms of chlorine = 3.45 x 6.022x 10 ^23 x 1
= 2.078x10^24
( to find no. of atoms of, heres the formula i was taught No. of atoms = no. of moles x Avogadros constant x no. of atoms in the formula of compound)
What improvements have been made in modern farming? Select all that apply.
1. machines can do more work over less time
2. better seeds sprout and grow much more quickly
3. trains can transport food over long distances faster
4. trains can transport the machines to rural farms once built
5. insecticides used to keep insects off the crops
Answer:
all of them except number 2
Explanation:
Answer:
1,3,4,5 the other perosn is correct
Explanation: That what my quiz said
what are the possible values for standard temperature and pressure
Answer:
0 °C and 1 Atm,
Explanation:
Standard Temperature and Pressure. Standard temperature is equal to 0 °C, which is 273.15 K.
Standard Pressure is 1 Atm, 101.3kPa or 760 mmHg or torr
what is an example of a strong base?
HCl
NaCl
NaOH
HF
Answer:
The answer is NaOH
Explanation:
Strong bases are characterized by the fact that they dissociate completely in an aqueous solution. In this case, sodium hydroxide, NaOH, is classified as a strong base because it dissociates completely in an aqueous solution to form sodium cations, Na+, and hydroxide anions, OH−. Also, it is strong because it totally breaks in its ion. And the base which breaks totally in its atom called the strong base and which doesn't it that is a weak base.
Answer:
NaOH
Explanation:
Got it right in the test. Please mark as brainliest
What is the answer ?
Answer:
b
Explanation:
Electromagnetic waves are waves that have no medium to travel whereas mechanical waves need a medium for its transmission.
Which of these Electromagnetic waves has the most kinetic energy and can be
dangerous?
O radio waves
O gamma rays
O ultraviolet waves
O visible light
Answer:
Gamma Rays.
Explanation:
Gamma-ray photons have the highest energy in the EMR spectrum and their waves have the shortest wavelength.
Is the equation Zn+HCl > ZnCL2+H2 unbalanced or balanced
Answer:
unbalanced
Explanation:
Cl and H have an extra atom
- Hope that helps! Please let me know if you need further explanation.
What is El Nino and La Nina explained? Please help fast
Answer:
el nino: the boy
la nina: the girl
Explanation:
Answer:
el nino is dinosour la nino is fishcat
Explanation:
Fiona is examining a material. She notices that the material has a dull appearance and feels very brittle.
Fiona is most likely examining a _______
(I'll give brainliest)
"Typical nonmetals have a dull, coloured or colourless appearance; are brittle when solid; are poor conductors of heat and electricity; and have acidic oxides." - Wikipedia
what happens to the density of a box full of leaves if you crush up all the leaves and place them in another box
A the density increases
B the density stays the same
C the density decreases
D the density first decreases, then increases
Answer:
B the density stays the same
What is the mole fraction of Ba(OH)2 in an aqueous solution that contains 22.8% Ba(OH)2 by mass?
Answer:
0.03
Explanation:
22.8 g Ba(OH)2 (1 mol Ba (OH)2/ 171.34 g) = 0.133 mol Ba (OH)2
77.2 g H2O (1 mol H2O/18 g) = 4.29 mol H2O
X= molar fraction= mol Ba(OH)2/ mol total
X= 0.133/ (0.133+4.29) = 0.03
0.03 is the mole fraction of [tex]Ba(OH)_2[/tex] in an aqueous solution that contains 22.8% [tex]Ba(OH)_2[/tex] by mass.
What is a mole fraction?The ratio of the number of moles of one component of a solution or other mixture to the total number of moles representing all of the components.
Moles of [tex]Ba(OH)_2[/tex]
Moles = [tex]\frac{mass}{molar \;mass}[/tex]
Moles = [tex]\frac{22.8 g Ba(OH)_2}{171.34 g}[/tex]
= 0.133 mol [tex]Ba (OH)_2[/tex]
Moles of [tex]H_2O[/tex]
[tex]Moles = \frac{mass}{molar \;mass}[/tex]
[tex]Moles = \frac{77.2 g H_2O}{18 g}[/tex]
= 4.29 mol [tex]H_2O[/tex]
The mole fraction of [tex]Ba(OH)_2[/tex]
[tex]\frac{mol Ba(OH)_2}{total \;mol}[/tex]
= 0.03
0.03 is the mole fraction of [tex]Ba(OH)_2[/tex] in an aqueous solution that contains 22.8% [tex]Ba(OH)_2[/tex] by mass.
Learn more about the mole fraction here:
https://brainly.com/question/8076655
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Which sentence best describes part of the process for generating electricity in a nuclear power plant?
A.Atoms Join together to produce water molecules.
B.An atom releases electrons, producing an electric current.
C.Protons and neutrons Join together to create atoms.
D.Heat is released when atomic nuclel split.
Answer:it is D
Explanation: it is only one that makes sense
The only thing that makes one kind of light different from another is it’s ____?
A) frequency
B) color
C) wavelength
D) temperature
Why were scientists surprised to find coal in the arctic?
Answer:
coal is made from compressed plant matter and how exactly did plants grow on the surface of an ocean. (as there is no land mass beneath the arctic.)
Explanation:
it would be like finding a fly in an ice cube to simplify it.
They were surprised to find coal in arctic because ordinarily coal was supposed to be found in warm or hot environments and not cold region like the arctic.
The arctic is located at the far northern part of the world which is characterized by its extreme cold weather.
A limited vegetation of plants such as grasses, mosses and lichens are found in this region irrespective of the extreme cold weather through out the year.
Coal is a type of fuel gotten from fossils and deposits of plant vegetation.
Scientist has discovered that continents do move over time through a process called continental drift. This is the reason why limited vegetaion is found in the arctic leading to the formation of coal.
Learn more here:
https://brainly.com/question/22647554
Balance the following equation by adding the correct mole numbers.
P⁴+Cl²->PCl³
Hey there!
P₄ + Cl₂ → PCl₃
First, let's balance Cl.
There are 2 on the left, and 3 on the right.
To balance this, let's put a coefficient of 3 in front of Cl₂ and a coefficient of 2 in front of PCl₃.
P₄ + 3Cl₂ → 2PCl₃
Now we have 6 on the left and 6 on the right.
Next, let's balance P.
There are 4 on the left and 2 on the right.
Let's change the coefficient in front of PCl₃ from 2 to 4.
P₄ + 3Cl₂ → 4PCl₃
There are now 4 P on each side.
However, now Cl is unbalanced, with 6 on the left and 12 on the right.
We can change the coefficient in front of Cl₂ from 3 to 6.
P₄ + 6Cl₂ → 4PCl₃
So now, we have 4 P on each side and 12 C on each side.
This is our final balanced equation.
Hope this helps!
Answer:
1:1
Explanation:
Took test
ASAP NEED HELP PLSSS
A gas occupying a volume of 3.75L at a pressure of 0.980 arm is allowed to expand at constant temperature until its pressure reaches 0.641 atm. What is the final volume of the sample?
Answer:
Volume = 5.73L
Explanation:
Data;
V1 = 3.75L
P1 = 0.980atm
P2 = 0.641atm
V2 = ?
This question involves the use of Boyle's law, which states that, the volume of a fixed mass of gas is inversely proportional to its pressure provided that temperature remains constant.
Mathematically,
V = kP, k = PV
P1V1 = P2V2 =P3V3=........=PnVn
P1V1 = P2V2
V2 = (P1 * V1) / P2
V2 = (0.980 × 3.75) / 0.641
V2 = 5.73L
The final volume of the gas is 5.73L
A typical cell phone uses wavelength of 0.36meters. How much energy does this wave have?
Answer:
55×10^-26 J
Explanation:
We can calculate the energy of the wave from
E= hc/λ
Where
h= Planks constant = 6.6×10^-34 Is
c= speed of light = 3×10^8 ms-1
λ= wavelength of the wave = 0.36 metres
Recall that cell phone use radio waves which belong to the electromagnetic spectrum hence it must possess the speed of light.
E= 6.6×10^-34 × 3×10^8/ 0.36
E= 55×10^-26 J
Hence the energy possessed by 0.36 meters wavelength radio waves is 55×10^-26 J
when the surface of a mirror curves inward, like the inside of a bowl, it is called a ____.
A) plane mirror
B) convex mirror
C) concave mirror
D) diffuse mirror
Answer:
C
Explanation:
The answer is always C
Answer:C. Concave mirror
Explanation:
When the surface of a mirror curves inward, like the inside of a bowl, it is called c. Concave mirror.
Help me!
what is the biggest disadvantage of using nuclear power to produce electricity?
a. nuclear fission releases more air pollution than burning coal
b. nuclear fission produces less energy than burning coal or oil.
c. nuclear waste must be safely stored for many years
d. nuclear waste must be incinerated
The biggest disadvantage of using nuclear power to produce electricity is the nuclear waste must be safely stored for many years.
What is nuclear power?Nuclear power is the use of nuclear reactions to produce electricity. Nuclear power can be obtained from:
Nuclear fission Nuclear decay and Nuclear fusion reactionsNuclear reactions produces high amount of energy and many waste materials which are non degradable and will stay in the environment for the long time.
Hence, nuclear waste must be safely stored for many years.
To know more about nuclear power, visit the below link:
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