In a chemical reaction, there is a change in the composition of the substances in question; in a physical change there is a difference in the appearance, smell, or simple display of a sample of matter without a change in composition.
A chemical change is a change where something new can be formed and normally can not be changed back. Examples of a chemical change are precipitates being formed, gases being formed, quick temperature change rust, bubbling, foaming, burning, etc. A physical change is a change where nothing new is formed and normally can be changed back. For example you painted a wooden block red. If you want, you can always change the color again. Nothing chemically or permanantly happened to it. More examples of a physical change are; color change, change of state, luster, shape, size, hardeness, etc.
:)
(i) A vessel of 110 mL capacity contains a certain amount of gas at 33 "C and 2.4 bar pressure. The gas is transferred to another vessel of volume 160 mL at 33 °C. What would be its pressure?
(ii)On a ship sailing in Ocean where temperature is 26.2degree Celsius a balloon filled with 4L air. What will be the volume of the balloon when the ship reaches Indian Ocean, where temperature is 38.1 degree Celsius?
Answer:
a) 1.65 bar
b) 4.2 L
Explanation:
From Boyle's law(since temperature is constant);
P1V1= P2V2
P2 = P1V1/V2
V1 = 110 ml
T1= 33 + 273 =306 K
P1 = 2.4 bar
V2 = 160 ml
T2 = 33 + 273 = 306
P2 =?
P2 = 2.4 * 110/160
P2 = 1.65 bar
2)
T1 = 26.2 + 273 = 299.2 K
V1 = 4L
T2 = 38.1 + 273 = 311.1
V2 =?
From Charles's law;
V1/T1 = V2/T2
V1T2 = V2T1
V2 = V1T2/T1
V2 = 4 * 311.1/299.2
V2 = 4.2 L
What is the sodium sulfide positive ion and negative ion?
Answer:
Poyo
Explanation:
What is the energy of a photon (J) that has a wavelength of 105 nm?
Answer:
3.46
⋅
10
−
19
J
The energy of a photon is proportional to its frequency, as stated by the Planck - Einstein's equation
E
=
h
⋅
ν
, where
E
- the energy of the photon
h
- Planck's constant, equal to
6.626
⋅
10
−
34
J s
ν
- the frequency of the photon
Now, notice that you are given the wavelength of the photon,
λ
. As you know, frequency and wavelength have an inverse relationship described by the equation
λ
⋅
ν
=
c
, where
c
- the speed of light in vacuum, approximately equal to
3
⋅
10
8
m s
−
1
This means that the relationship between energy and wavelength looks like this
λ
⋅
ν
=
c
⇒
ν
=
c
λ
E
=
h
⋅
c
λ
Another important thing to notice here is that the wavelength of the photon is given in nanometers,
nm
. You need to convert this to meters, the unit used for the value of the speed of light.
E
=
6.626
⋅
10
−
34
J
s
⋅
3
⋅
10
8
m
s
−
575
⋅
10
−
9
m
=
3.46
⋅
10
−
19
J
Explanation:
Brainliest please?
The Calories on a food label indicate the
amount of energy the food contains in
one serving. Which form of energy is
contained in food?
Answer:
chemical energy
Explanation:
Caleb is an inventor who has designed a new kind of fishing net. He is looking for a strong, flexible material that can be used to hold a lot of weight and will not dissolve in water. He wants a synthetic material so he does not have to depend on harvesting a natural product.
NEED CORRECT
Which material would be best for Caleb’s invention?
cellulose
nylon
polystyrene
vulcanized rubber
Answer:
Its B Nylon
Explanation:
i just took the quiz and got it right.
Answer:
nylon
Explanation:
nylon is a common material used for nets and it is strong
what information does a chemical equation contain
Answer:
Chemicals should involve information about properties and reactants.
6 Which of the following would provide the best evidence that air is made of matter? A Making a small hole in a tire and measuring the amount of time it takes for it to become flat B Comparing the mass and volume of an empty balloon to the mass and volume of an inflated balloon C Measuring the temperature of the air in several rooms of varying sizes D Finding the volume of the air between marbles in a jar by pouring water over them
If hydrochloric acid has a [H+] of 1.2 x 10-2 M, what is the pH?
1.9
0 1
1.2
O
8
Answer:
1.9Explanation:
The pH of a solution can be found by using the formula
[tex]pH = - log [ {H}^{+} ][/tex]
From the question we have
[tex]pH = - log(1.2 \times {10}^{ - 2} ) \\ = 1.920818...[/tex]
We have the final answer as
1.9Hope this helps you
Answer:
1.9
Explanation:
pleaseeee help me solve this answer
Answer:
A open system
I think plz tell me if i'm wrong
Explanation:
Answer:
A- an Open System
Explanation:
A sound with more vibrations per second sounds higher than a sound with fewer vibrations per second.
Lesson 4.07
Question 9 options:
True
False
Answer:
that is a false sentence
Answer:
I'm sure you've already finished the est but the real answer is true, I took the k12 test and got that one correct, hope this helps anyone!
Explanation:
Which example describes a chemical change
taking place?
A. water turning into steam
B. sugar dissolving in warm water
C. alcohol evaporating from a food while baking
D. nails rusting while sitting outside
Which chemical equation is balanced?
OA CO, + H,0 - H,CO,
O8 Mg0+ 2HCI - MgCly + H,0
O0 Ca0, + HCI CaCl, + H,0
O0K H,0- K,0 +H,
The chemical balanced : A and B
Further explanationGiven
Chemical equation
Required
Balanced equation
Solution
A chemical equation is said to be balanced if the number of atoms in the reactants and the number of atoms in the product are the same
a. CO₂+H₂O⇒H₂CO₃
balanced
b. MgO+ 2HCI ⇒ MgCl₂ + H₂O
balanced
c. CaO + HCI ⇒ CaCl₂ + H₂O
the elements H and Cl are not balanced
d. K + H₂O ⇒ K₂O +H₂
element K is not balanced
State five differences between compound and mixtures in a tabular form
Answer:
The differences between compound and mixtures in a tabular form are as follow:
Both are written differently. Plz do write by making table at once.
Hope it help you
determine the frequency and wavelength (in nm) of the light emitted when the e- fell from n=4 and n=2
Answer:
Frequency = 6.16 ×10¹⁴ Hz
λ = 4.87×10² nm
Explanation:
In case of hydrogen atom energy associated with nth state is,
En = -13.6/n²
For n = 2
E₂ = -13.6 / 2²
E₂ = -13.6/4
E₂ = -3.4 ev
Kinetic energy of electron = -E₂ = 3.4 ev
For n = 4
E₄ = -13.6 / 4²
E₄ = -13.6/16
E₄ = -0.85 ev
Kinetic energy of electron = -E₄ = 0.85 ev
Wavelength of radiation emitted:
E = hc/λ = E₄ - E₂
hc/λ = E₄ - E₂
by putting values,
6.63×10⁻³⁴Js × 3×10⁸m/s / λ = -0.85ev - (-3.4ev )
6.63×10⁻³⁴ Js× 3×10⁸m/s / λ = 2.55 ev
λ = 6.63×10⁻³⁴ Js× 3×10⁸m/s /2.55ev
λ = 6.63×10⁻³⁴ Js× 3×10⁸m/s /2.55× 1.6×10⁻¹⁹ J
λ = 19.89 ×10⁻²⁶ Jm / 2.55× 1.6×10⁻¹⁹ J
λ = 19.89 ×10⁻²⁶ Jm / 4.08×10⁻¹⁹ J
λ = 4.87×10⁻⁷ m
m to nm:
4.87×10⁻⁷ m ×10⁹nm/1 m
4.87×10² nm
Frequency:
Frequency = speed of electron / wavelength
by putting values,
Frequency = 3×10⁸m/s /4.87×10⁻⁷ m
Frequency = 6.16 ×10¹⁴ s⁻¹
s⁻¹ = Hz
Frequency = 6.16 ×10¹⁴ Hz
Scientists were studying three different embryos to determine their relationship to humans. The notes about each embryo are shown in the chart. Based on the information, what can you determine?
Answer:
Species A and C are related to humans.
Explanation:
got it right on edge.
Answer:A. Species And C are related to humans
Explanation: In the embryo humans and other Species have gill slits, and a tail. Vestigesof tales grew and non-human ancestors. On rare occasions, aremnant of the tail through and embryological development, although this tale of course has no function. An embryos splits are found in the boreals of all vertebrates because they share a common ancestors with fish and which structures first
Mike mixes two chemicals in a container. The container quickly becomes
very hot
What can be said about this reaction?
Answer:
it is an exothermic reaction
What are the needs & advantages of career planning?
in the blanks using the options given below:
Career is a sequence of related jobs arranged in a .........order.
Wrong choice of career may lead to.................
Agriculture, veterinary and nursing provide better........ ... to
young people.
Poor health and safety condition in an organization
causes.................effect on the choice of career.
The essence of career planning is the................ of individual goal
with organizational goal.
gative, hirarchical, frustration, bridging, lucrative, attraction
Answer:
The correct options are;
1) Hierarchical
2) Frustration
3) Attraction
4) Gative
5) Bridging
Explanation:
A career can be defined as a person's trade or occupation, which he or she engages and progresses in for a considerable portion of his or her life
When a person is engaged in a career that is not best suited to them can therefore lead to frustration, due to the length of time required in building a career
Agriculture, veterinary and nursing are mainly hands on or time input (for agriculture) careers, that seek to attract young people
The existence of poor health and safety conditions in an organization limits the advancement of individuals in their chosen career within the organization
Therefore, we have;
Career is a sequence of related jobs arranged in a hierarchical order
Wrong choice of career may lead to frustration
Agriculture, veterinary, and nursing provide better attraction to young people
Poor health and safety conditions in an organization causes gative effect on the choice of career
The essence of career planning is the bridging of individual with organizational goal.
Select the correct answer from each drop-down menu
The rock cycle
Answer:
The picture?
Explanation:
Please the picture
This makes no sence. Please put the picture up for us to answer. Thanks!
what is a metorlogist
an expert in or student of meteorology; a weather forecaster.
What signs of a chemical reaction did you observe during the lab? Check all that apply.
color change
temperature change
mass change
formation of a gas
formation of a solid
formation of a liquid
Answer:
1, 4, 5
Explanation:
1 - Color Change
4 - Formation of Gas
5 - Formation of Solid
(correct on ed)
Answer: A, D , E
Explanation:
What type of element makes a positive
cation?
Answer:
The answer would be Metals.
Which of the following describes scientists?
A. People with perfect understanding of science
B. People from different backgrounds
C. People with only one perspective
D. People with similar personalities
Answer:
A. People with perfect understanding of science
Status
Exam
HF is
an acid
a base
neither an
acid nor a
base
Copyright © 2003 - 2020 Acellus Corporation. All Rights Reserved.
Is HF a base, acid or non
Answer:
HF is an acid as it losses hydrogen into the sollution on hydrolysis.
Explanation:
are the 14 transition metals that follow lanthanum in the periodic table.
Answer: Lanthanide or Lanthanides
Explanation: Sorry that I don’t have an explanation. I just answered the question correctly myself. <33
The lanthanide and actinide are present in the periodic table as a transition metals.
What is periodic table?Periodic table is defined as a tabular arrangement of chemical elements ordered by increasing atomic number and element groups.
The latest periodic table has an ordered grouping of the 118 known chemical elements.
Lanthanide is defined as any of the elements with rising atomic numbers beginning with lanthanum or cerium and ending with lutetium.
Lanthanide are rarely found on earth i.e. they are called rare earth metals.
Actinide is defined as any of the elements with increasing atomic numbers beginning with actinium or thorium and ending with lawrencium.
Actinide are the radioactive metals.
Thus, the lanthanide and actinide are present in the periodic table as a transition metals.
To learn more about periodic table, refer to the link below:
https://brainly.com/question/11155928
#SPJ2
How does kinetic energy relate to particles and the states of matter?
Help??
Answer:
The kinetic molecular theory of matter states that: Matter is made up of particles that are constantly moving. Molecules in the solid phase have the least amount of energy, while gas particles have the greatest amount of energy. The temperature of a substance is a measure of the average kinetic energy of the particles.
Explanation:
Hope this helps. Happy Holidays!!!!
what is dark matter
can we travel faster than speed of light
what is chlorophyll
Answer:
Explaining dark matter and black holes
Here are six big questions about our universe that current physics can’t answer:
What is dark energy, the mysterious energy that appears to be accelerating the expansion of the universe?
What is dark matter, the invisible substance we can only detect by its gravitational effect on stars and galaxies?
What caused inflation, the blindingly fast expansion of the universe immediately after the Big Bang?
For that matter, what caused the Big Bang?
Are there many possible Big Bangs or universes?
Is there a telltale characteristic associated with the death of a universe?
Despite the efforts of some of the world’s brightest brains, the Standard Model of particle physics – our current best theory of how the universe works at a fundamental level – has no solution to these stumpers.
A compelling new theory claims to solve all six in a single sweep. The answer, according to a paper published in European Physical Journal C by Herb Fried from Brown University and Yves Gabellini from INLN-Université de Nice, may be a kind of particle called a tachyon.
Tachyons are hypothetical particles that travel faster than light. According to Einstein’s special theory of relativity – and according to experiment so far – in our ‘real’ world, particles can never travel faster than light. Which is just as well: if they did, our ideas about cause and effect would be thrown out the window, because it would be possible to see an effect manifest before its cause.
Alt
Explanation:
Due to travelling faster than light, dark matter has a higher than usual mass in relation to its resting mass, thus accounting for the large 'missing' mass around galaxies. ... Dark matter is therefore non-baryonic, travelling faster than light and has a mass half that of a photon...
bts army forever.....vzgGgzs0
.......JK
.....justin bieber
Examine the EM spectrum chart. Describe what is happening as the EM spectrum goes
from Radio Waves to Gamma rays,
Vight
Uno
Somme
Morowaves
Infrared
Radio Waves
Woman
w
w
Wavelength
The amplitude increases
The wavelength increases
The wavelength decreases
The amplitude decreases
Answer:
The wavelength decreases
Explanation:
As you go along the EM spectrum from radio waves to gamma rays, the wavelength decreases as the wave's energy and frequency increase.
Question 10 of 32
Which of the following is an example of how the same chemicals used to
help people can harm the environment?
O A. Phosphates are removed from detergents so they don't end up in
drinking water.
B. Hillsides erode after plants are removed to clear a space for crops.
C. Plants grow back after toxic chemicals are removed from the
surrounding soil.
D. Excess fertilizers run off into rivers and create a dead zone.
SUBMIT
Answer:
D
Explanation:
The correct answer that gives a good example of how the same chemical used to help people can harm the environment would be when excess fertilizers run off into rivers and create a dead zone.
Fertilizers are usually applied to crops as an agricultural practice by farmers to enhance the yield of the crops and boost food or raw materials production. However, excess fertilizer gets washed into nearby water bodies and ends up creating a low-oxygen zone that is incapable of supporting lives within the water body - also known as dead zones.
The correct option is, therefore, D.
Nitrogen gas is cooled and its volume went
from 375 mL to 255 mL. If the final
temperature is -45 °C, what was the original
temperature?
In the ground state, all of the atoms of Period 3 elements have the same
A) atomic number
B) number of oxidation states
C) number of occupied energy shells
D) atomic mass
Answer:
C) number of occupied energy shells
Explanation:
Atomic numbers of different elements must differ, as well as atomic masses. The number of oxidation states differs per atom as well.
