at what temperature does a solid turn into a liquid
Answer:
0°C
Hope this helps Do mark as brainliestAnswer:
a little over 0 degrease cel
Explanation:
Which of the following is most likely NOT a chemical reaction?
(A)
A white powder and a clear liquid mix and the beaker holding the mixture gets cool to the touch
(B)
A white solid and a clear liquid mix and produce a bright orange, bubbling substance
(C)
A pan containing a clear liquid is place on a hot stove and begins to bubble after a few minutes.
(D)
A blue liquid and a green solid mix and produce a purple paste
Answer:
B is the correct answer because bubbling is a sign of chemical reaction and production of a new substance
Which of the following is an irreversible physical change?
a) melting a piece of lead
b) sharpening a pencil
c) dissolving sugar into water
d) boiling water
Answer:
b) sharpening a pencil
Explanation:
If you melt lead, boil water, or dissolve sugar in water, you can return all of them back to their original state. If you sharpen a pencil, you can't reattach the shavings as they were originally.
You may put all of them back to their original states by melting lead, heating water to a boil, or dissolving sugar in water. You cannot rejoin the shavings from a sharpened pencil in their original position. Thus, option B is correct.
What is irreversible physical change?When something changes physically but not chemically, it has undergone an irreversible physical alteration that cannot be reversed.
Sharpening a pencil is a perfect example of an irreversible physical change. The wood turns to dust when you sharpen it. Just in a different shape, it is still wood. That wood dust cannot be transformed back into a pencil.
You cannot put a piece of paper back together the same way it was before you tore it if you tear it into tiny pieces.
An irreversible alteration is one that cannot be undone or that cannot be returned to its original state, such as when milk turns into curd, iron turns rusty, paper burns, food is cooked, etc.
Therefore, sharpening a pencil is an irreversible physical change
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Which describes the motion of the car as shown by the graph?
A) travels at a constant speed
B) not moving
C) changing directions
D) speeding up
Define a force.......
Answer:
Gravitational Force.
Gravitation is the agent that gives weight to objects with mass and causes them to fall on the ground when dropped.
Answer:
A force is the strength or energy as an attribute of physical action or movement.
Explanation:
In smaller words, a force is a form of energy caused from a push or a pull on an object. A force happens when two objects interact with each other. For example, when you throw a ball you are using force.
Hopefully this helps im sorry if i got it wrong im kinda dumb... XD
With some manipulation, the Rydberg equation can be rewritten in the form
E=constant×(1nf2−1ni2)
which allows you to calculate the energy of the emitted light. Express this constant in terms of the constants h, c, and RH using relationships between wavelength and energy as well as the Rydberg equation from the introduction.
Express the constant in terms of h and c, and RH.
Please help me with this question?
Answer:
attached below is the detailed solution
answer : value of constant = 2.18 * 10^-18 J
Explanation:
Express the constant in terms of h and c and RH
attached below is the detailed solution
Constant = [tex]h_{C} R_{H}[/tex]
= ( 6.626 * 10^-34 ) * ( 3 * 10^8 ) * ( 1.097 * 10^7 )
= 2.18 * 10^-18 J
The Planck equation and the light speed allow us to find the results for the transformation of the Rydberg equation are:
[tex]E = A ( \frac{1}{n_1^2}\frac{x}{y} - \frac{1}{n_2^2} )\\A= R_H \ h \ c \\A = 2.18 \ 10^{-18} j[/tex]
The Rydberg equation is an empirical expression that explains the wavelength of the emissions.
[tex]\frac{1}{\lambda } = R_H ( \frac{1}{n_1^2} - \frac{1}{n_2^2} )[/tex]
Where λ is the wavelength of the emitted radiation, is the Rydberg constant, n₁ and n₂ are integers with n₁ <n₂
It is asked to write the Rydberg equation for the energy.
Let's use the Planck relation.
E = h f
The light speed is related to the wavelength and frequency of radiation.
c = λ f
Where E is the energy, h the Planck constant, c the speed of light, λ the wavelength and f the frequency.
Let's substitute.
E = [tex]\frac{hc}{\lambda}[/tex]
[tex]\frac{1}{\lambda} = \frac{E}{hc}[/tex]
Let's substitute in the Rydberg equation.
[tex]\frac{E}{hc} = R_H ( \frac{1}{n_1^2} - \frac{1}{n_2^2}) \\E = R_H \ h \ c \ ( \frac{1}{n_1^2} - \frac{1}{n_2^2} )[/tex]
We can write is an constant of the form.
A = [tex]R_H h c[/tex]
The value of the constant is :
A = 1,097 10⁷ 6,626 10⁻³⁴ 3 10⁸
A = 2.18 10⁻¹⁸ J
In conclusion, using the Planck equation and the light speed we can find the results for the transformation of the Rydberg equation are
[tex]E = A ( \frac{1}{n_1^2} - \frac{1}{n_2^2} )\\ A = R_H h c\\[/tex]
A = 2.18 10⁻¹⁸ J
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Burning is a type of_________reaction.
O replacement
O decomposition
O synthesis
O combustion
Answer:
Combustion
Explanation:
Happy Halloween!
Sodium + oxygen
What colour is the flame produces
Answer:
Orange
Explanation:
I used google my b
Answer:
ORANGE
explanation:
Small pieces of sodium burn in air with often little more than an orange glow. Using larger amounts of sodium or burning it in oxygen gives a strong orange flame.
The momentum of a 23 000 kg truck traveling eastward with a velocity of 50.0 m/s is kom/s
Answer:
Explanation:
I'm not sure what you mean by the units. The answer using kg and ms is 23000 * 50 = 1150000 kg m/s
What is the rule of zero charge?
Answer:
The nonmetal atoms accept electrons and form ions with a negative charge, called anions. When an ionic compound forms, the total charge on the atoms adds up to zero. This is known as the rule of zero charge.
Explanation:
How many electrons does each lithium atom provide to the voltaic cell?
A. 1
B. 2
C. 3
D. 4
Answer:
c. 3 electrons
Explanation: for the element of LITHIUM, you already know that the atomic number tells you the number of electrons. That means there are 3 electrons in a lithium atom.
Select the correct answer.
In which situation is no work considered to be done by a force?
A.
when the angle between the force and displacement is 180°
B.
when the angle between the force and displacement is 90°
C.
when the angle between the force and displacement is 45°
D.
when the angle between the force and displacement is 0°
Answer:
Explanation:
when the angle between the force and displacement is 0
What element would have this electron configuration:
1s22s22p5
which element would have properties most like arsenic (As)? Te Ge P Se
Answer:
P
Explanation:
Which of the following has a higher electronegativity oxygen or selenium?
Answer: Oxygen
Explanation: Oxygen has more ionisation energy and Oxygen has a small size which makes it more electronegative.
The millions of fossils that scientists have collected are called the fossil __.
Answer:
record
Explanation:
Atomic number is equal to the number of electrons in an atom?.
Answer:
true I think not sure
Explanation:
Sodium, an alkali metal, and chlorine, a halogen, are both in Period 3 of the periodic table. Which element has
a higher ionization energy? Explain your answer.
Answer:
Chlorine has higher ionization energy.
Explanation:
Sodium is present on left side of periodic table in period 3 while chlorine is present on right side of periodic table in period 3.
As we move from left to right across the periodic table the number of valance electrons in an atom increase. The atomic size tend to decrease in same period of periodic table because the electrons are added with in the same shell. When the electron are added, at the same time protons are also added in the nucleus. The positive charge is going to increase and this charge is greater in effect than the charge of electrons. This effect lead to the greater nuclear attraction. The electrons are pull towards the nucleus and valance shell get closer to the nucleus. As a result of this greater nuclear attraction atomic radius decreases and ionization energy increases because it is very difficult to remove the electron from atom and more energy is required. Thus chlorine have higher ionization energy as compared to the sodium.
Which two types of information are found in an element's box in the periodic
table?
A. Atomic number
B. Chemical symbol
O C. Chemical formula
O D. Atomic structure
( TWO ANSWERS)
The information we can obtain for an element from periodic table is its atomic number and chemical symbol. Thus option A and B are correct.
What is atomic number?Atomic number of an element is the number of protons of the element. For a neutral atom the number of electrons is equal to the number of protons.
There are 118 elements in the modern periodic table and they are classified into different group and periods. Elements of same number of valence electrons and similar physical and chemical properties are classified into one group.
There are 18 groups and 7 period in the periodic table. Each classification is based on their atomic number. Chemical symbols are used to represent the elements and they can be easily identified by the symbols.
For example, hydrogen have the chemical symbol H and oxygen with O and carbon with C. etc. Similarly we can get mass number of elements from periodic table. Thus option A and B are correct.
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HELPPP PLEASEEE!!! calculate the energy of radiation with a wavelength of 432 nm
Define the concept of Energy in your own words
Answer:
In general, the word energy refers to a concept that can be paraphrased as "the potential for causing changes", and therefore one can say that energy is the cause of any change. The most common definition of energy is the work that a certain force (gravitational, electromagnetic, etc) can do. Due to a variety of forces, energy has many different forms (gravitational, electric, heat, etc.) that can be grouped into two major categories: kinetic energy and potential energy. According to this definition, energy has the same units as work; a force applied through a distance. The SI unit of energy, the joule, equals one newton applied through one meter, for example. Energy has no direction in space, and is therefore considered a scalar quantity. Energy is a conserved quantity, meaning that it cannot be created or destroyed, but only converted from one form into another. Thus, the total energy of the universe always remains constant. One form of energy can be readily transformed into another; for instance, a battery converts chemical energy into electrical energy.
Explanation:
What advances in technology helped usher in the scientific revolution? Choose the best answer.
1.The landing on the Moon by Apollo brought about the scientific revolution.
2.Discoveries by scholars in the Catholic Church revolutionized scientific knowledge.
3.The discoveries by ancient Greek, Muslim and Chinese scientists.
4.The discovery of optics gave scientists instruments such as microscopes and telescopes.
Answer:
The discovery of optics gave scientists instruments such as microscopes and telescopes.
Explanation:
The period between the 16th-8th century was called the period of the scientific revolution. At this time, the foundations of our modern science was laid.
One of the characteristic of this period was the emphasis on the scientific method which upheld results from reproducible experiments.
Nicolaus Copernicus, Francis Bacon and Isaac Newton were leading names in this period.
It was within this period that the discovery of optics gave scientists instruments such as microscopes and telescopes and scientific examination of the celestial bodies was launched.
Explain how the igneous rock granite forms. Then tell how the granite might become the sedimentary rock sandstone and then the metamorphic rock quartzite.
Answer:
There are three main types of rocks: sedimentary, igneous, and metamorphic. Each of these rocks are formed by physical changes—such as melting, cooling, eroding, compacting, or deforming—that are part of the rock cycle. Sedimentary Rocks Sedimentary rocks are formed from pieces of other existing rock or organic material. There are three different types of sedimentary rocks: clastic, organic (biological), and chemical. Clastic sedimentary rocks, like sandstone, form from clasts, or pieces of other rock. Organic sedimentary rocks, like coal, form from hard, biological materials like plants, shells, and bones that are compressed into rock. The formation of clastic and organic rocks begins with the weathering, or breaking down, of the exposed rock into small fragments. Through the process of erosion, these fragments are removed from their source and transported by wind, water, ice, or biological activity to a new location. Once the sediment settles somewhere, and enough of it collects, the lowest layers become compacted so tightly that they form solid rock. Chemical sedimentary rocks, like limestone, halite, and flint, form from chemical precipitation. A chemical precipitate is a chemical compound—for instance, calcium carbonate, salt, and silica—that forms when the solution it is dissolved in, usually water, evaporates and leaves the compound behind. This occurs as water travels through Earth’s crust, weathering the rock and dissolving some of its minerals, transporting it elsewhere. These dissolved minerals are precipitated when the water evaporates. Metamorphic Rocks Metamorphic rocks are rocks that have been changed from their original form by immense heat or pressure. Metamorphic rocks have two classes: foliated and nonfoliated. When a rock with flat or elongated minerals is put under immense pressure, the minerals line up in layers, creating foliation. Foliation is the aligning of elongated or platy minerals, like hornblende or mica, perpendicular to the direction of pressure that is applied. An example of this transformation can be seen with granite, an igneous rock. Granite contains long and platy minerals that are not initially aligned, but when enough pressure is added, those minerals shift to all point in the same direction while getting squeezed into flat sheets. When granite undergoes this process, like at a tectonic plate boundary, it turns into gneiss (pronounced “nice”). Nonfoliated rocks are formed the same way, but they do not contain the minerals that tend to line up under pressure and thus do not have the layered appearance of foliated rocks. Sedimentary rocks like bituminous coal, limestone, and sandstone, given enough heat and pressure, can turn into nonfoliated metamorphic rocks like anthracite coal, marble, and quartzite. Nonfoliated rocks can also form by metamorphism, which happens when magma comes in contact with the surrounding rock. Igneous Rocks Igneous rocks (derived from the Latin word for fire) are formed when molten hot material cools and solidifies. Igneous rocks can also be made a couple of different ways. When they are formed inside of the earth, they are called intrusive, or plutonic, igneous rocks. If they are formed outside or on top of Earth’s crust, they are called extrusive, or volcanic, igneous rocks. Granite and diorite are examples of common intrusive rocks. They have a coarse texture with large mineral grains, indicating that they spent thousands or millions of years cooling down inside the earth, a time course that allowed large mineral crystals to grow.
Alternatively, rocks like basalt and obsidian have very small grains and a relatively fine texture. This happens because when magma erupts into lava, it cools more quickly than it would if it stayed inside the earth, giving crystals less time to form. Obsidian cools into volcanic glass so quickly when ejected that the grains are impossible to see with the naked eye. Extrusive igneous rocks can also have a vesicular, or “holey” texture. This happens when the ejected magma still has gases inside of it so when it cools, the gas bubbles are trapped and end up giving the rock a bubbly texture. An example of this would be pumice.
Explanation:
oh and also nice profile pic :P
Which ecosystem is the least stable?
Answer:
tundra bc it has barley any food source and has vary little inhabitants
Explanation:
Answer:
a patch of lichens on bare rock
Record the length of the object shown.
Answer: 7.26 mm
I did the test already.
(b) Define, in terms of oxidation state, the Oxidizing agent
a substance which gains oxygen
a substance whis lose hydrogen
a substance which experiences a decrease in oxidation state
a substance which experiences an increase in oxidation state
Answer: a substance whis lose hydrogen
Explanation:
Sugar is added to iced tea and the contents are stirred until all of the sugar dissolves. How would the tea now be classified?
What is involved in weathering?
Answer:
the answer is water.Hope this helps
• True False estion 2 (1 point) Water and ice are made from the same molecule H2O True False
Answer:
true i think
Explanation:
I’ll give the Brainliest, you also need to explain how the answer you got is correct.
Choose the best description of a neap tide.
A. Neap tides produce during the highest tides of the month.
B. Neap tides happen during winter and summer.
C. Neap tides could be described as low high tides and high low tides.
D. A neap tide is the period halfway between tides when the tide changes direction.
Thank you!
Answer:
D. A neap tide is the period halfway between tides when the tide changes direction. (correction) Answer : C
Explanation:
Process of elimination can be used. First off, A is incorrect because neap tides have the smallest tidal range ; spring tides would fit this choice. B is incorrect since neap tides are specific to the first, and third quarter moons when the sun and moon are right angles. C is wrong because it is the other way around since high tides are a little higher than average and low tides are a little lower than average (correction) this is correct since higher low tides and lower high tides are closer together and have a smaller tidal range than standard tides(spring tides) with higher high tides, and lower low tides. D is correct because they occur halfway between the spring tides (correction): incorrect since a neap tides occur around a week(7 days) after a spring tide(moderate tides). There is no evidence this is true.
There are three patterns: diurnal(one high and low tides a day), semidiurnal(two high and low tides a day), and mixed(two high and low tides a day of different lengths).
The spring and neap tides are the types of tides involved with the low and high tides.