Answer:
3.99 × 10 ^-28
Explanation:
In the equation of E = hc/λ, the h = 6.626 × 10^−34 J and c = 3 × 10^8 m/s
E = 6.626 × 10^−34 × 3 × 10^8 divided by 498
E = 3.99 × 10 ^-28
Classify the following properties of the element
silicon as chemical or physical properties:
a. blue-gray color
b. brittle
c. doesn't dissolve in water
d. melts at 1410°C
e. reacts vigorously with fluorine
We have that this how they differ
Physical properties
Blue-gray color BrittleChemical Properties
Doesn't dissolve in water Melts at 1410°C Reacts vigorously with fluorine
From the Question we are told that
Silicon properties:
a. blue-gray color
b. brittle
c. doesn't dissolve in water
d. melts at 1410°C
e. reacts vigorously with fluorine
Physical properties
This Refer to Properties that can be seen and Measured
While
Chemical Properties
This are Refers to the effect of the element in reactions
Therefore
Physical properties
Blue-gray color BrittleChemical Properties
Doesn't dissolve in water Melts at 1410°C Reacts vigorously with fluorineFor more information on this visit
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So I had a question which was, What is the charge on a neutron?
A. neutral
Bon positive
C. negative
(Which one of those is right choice?)
Answer:
A. neutral
Explanation:
It's net charge is 0.
Hope it is helpful....Answer:
A. neutral
Explanation:
A neutron is given by formular
[tex]» \: \: {}^{1}_{0}n[/tex]
hence it's net charge is zero
A dehydration reaction (or condensation reaction) is the process in which _____. See Concept 5.1 (Page) View Available Hint(s)for Part A water molecules are produced as a polymer is formed from monomers the bonds between the individual monomers of a polymer are broken by the addition of water molecules water molecules are attracted to each other water molecules are used as a source of raw material to break down polymers to monomers None of the choices is correct.
A dehydration reaction (or condensation reaction) is the process in which water molecules are produced as a polymer is formed from monomers.
A chemical reaction is the process by which substances called reactants are transformed to another substance known as products through the breaking up or building up of bonds between the reactants.
There are different types of chemicals reaction which includes condensation reaction.
Condensation reaction involves the combination of two smaller molecules known as monomers to for one larger molecule known as polymer with the loss of water molecule.
Condensation reaction is specifically called dehydration reaction due to the loss of water molecule that is involved.
Therefore, a dehydration reaction (or condensation reaction) is the process in which water molecules are produced as a polymer is formed from monomers.
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anyone know valency of phosphide and phosphite please tell me and also they are not same .If you know can i get their symbol too please
i found this. there's more coming up
The main difference between strong electrolytes and weak electrolytes is....
A. their jawline.
B. how much weight they can lift.
C. how smelly of a cheese they make.
D. how much they dissociate.
How does water vapor in the air change state below the freezing point
Answer:
Water vapor molecules in the air near the can cooled when energy from the air transferred to the cold can. These water molecules slowed down, condensed to liquid water, and then froze to become ice. Your can might have some water and some ice on the outside of it.
Explanation:
Why does the author include information about bread and sandwich wrappings in the article?
(A) to show that the scientific method is often used to understand things about food
(B) to provide an example of something that can be tested by the scientific method
(C) to demonstrate the problems that can be caused by improper seals and wrappings
(D) to help evaluate how the weight of bread can show how much moisture it has
Answer:
what is the story about actually.i think it's from ur lesson
Explanation:
certain breads mold easily...(fact)..
especially white bread., when exposed to any moisture, from refrigeration, or freezing..
when taken out of (cold environment), humidity in air causes molding because you take it from cold to/warm environment.
check expiration dates, keep refrigerated, and inspect 4 molding. Companies like WMART, buy in bulk, when on shelf, defrosts,, then has molding within expiration dates..
Which of the following are testable?
hypotheses
laws
theories
Answer: all of them
Answer:
all the above
Explanation:
. Arrange the following in order of increasing radius:
a) Mg2+, Na+, Al3+
b) Na+, Al3+ , Mg2+
c) Mg2+ , Al3+ , Na+
d) Al3+ , Mg2+, Na+
Answer:
d
Explanation:
because nuclear charge ( no. of protons) increases
Match each measurement to the correct number of significant figures it contains.
26.000 cm
0.800 km
0.00050 g
7300 m
3 x 10^5 mL
1
2
3
4
5
6
Answer:
Answer: a, b, c, d, e, f. a) 1 significant figure b) 3 significant figures c) 2 significant figures d) 4 significant figures e) 5 significant figures f) 6 significant figures Note that non-integers are rounded to the nearest integer and then count as the number of significant figures. For example, rounding 1.5 to two significant figures would mean one significant figure because it is an integer, not because it is a decimal.
Answer explanation: 26.000 cm = 2.6 x 10^2 cm. 0.800 km = 8 x 10^-3 km. 0.00050 g = 5 x 10^-4 g. 7300 m = 7.3 x 10^2 m. 3 x 10^5 mL = 3000000 ml or 300 L
Explanation:
How many significant figures are in each of these measurements?
32.14 cm
4.34 x 10^3 cm
2 g
13000 L
1.007 g/mL
6 mL
0.000005 L
2.7 mL
Answer: a, b and c contain 7 significant figures and the others each have 4 significant figures.
Incorrect answers indicate incorrect choices made for this problem or other problems on the worksheet . Answer explanation: 32.14 cm = 3.214 x 10^2cm 4.34 x 10^3cm = 4.34x10^5 cm 2 g = 2 grams 13000 L = 13 kiloliters 1.
during the interconversion of state of matter, mass undergoes and change? true or false
True.
The Mass Undergoes change only in ( Solid state to liquid state ) Ice Cube to Water .
Mass changes from mg to litre.
[tex]\huge\mathfrak\red{hope \: it \: helps}[/tex]
on what bases are the elements of periodic table classified?
The elements can also be classified into the main-group elements (or representative elements) in the columns labeled 1, 2, and 13–18; the transition metals in the columns labeled 3–12; and inner transition metals in the two rows at the bottom of the table (the top-row elements are called lanthanides and the bottom-row ...
Hello,
What are Elements?Elements are a group of the Periodic Table that shares common valence electron structures. They are arranged in order of increasing Atomic Number.
Now back to the question:-In modern periodic table they are classified into three parts- metals, non-metals and metalloids.
In detail:-
• Metals- Metals are those elements which donate electrons. Ex- Na, K, Rb, Mg, Ca, etc.
• Non-metals- Non-metals are those elements which accept electrons. Ex- N, O, F, Cl, etc .
• Metalloids- Metalloids are those elements which show property of both metals and non-metals. Ex- B, Si, Ge, etc.
Hope it helps...
(by Benjemin)
A car start from rest and covers distance of 100m after 10seconds.if the acceleration is 2m/s square, calculate the final velocity..
Answer:
20 m/s
Explanation:
solution,
initial velocity (u)=0 m/s
Distance covered(s)=100m
Time taken(t)=10 seconds
Acceleration (a)=2m/s²
Now,
By using first equation of motion, we have
v=u+at
=0+2×10
=20 m/s
I hope it helped U
stay safe stay happy
What is the difference between luminous objects and non luminous objects
Answer:
Objects that can emit light energy by themselves are known as luminous objects. Objects that cannot emit light energy by themselves are known as non-luminous objects.
Explanation:
Explanation:
Luminous objects:- The objects that can emit light energy by themselves are known as luminous objects.
Objects like the sun that give out or emit light of their own are luminous objects.
Other examples of luminous bodies are Electric bulb, torch etc.
Non-luminous objects:- the objects that can not emit light energy by themselves are known as Non- luminous objects.
Objects like the moon that do not give out or emit light of their own are Non- luminous objects.
Moon is an example of a non-luminous object as we can see the moon because it reflects light from the sun.
Other examples of Non luminous bodies are pen, pencil, chair, wood etc.
Luminosity – It is defined as the luminous intensity in a particular direction; or we can say it is the apparent brightness of an image.
The brightness of a star is defined as the total energy radiated in unit time. It is related to the surface area (A) and the effective temperature (TT) ( the temperature of a black body having the same radius as the star and radiating the same amount of energy per unit area in one second ) by a form of Stefan’s law, here is given by
⇒L=AσT4⇒L=AσT4
where
σ is the Stefan’s constant and L is the luminosity.
Note:
The laptop screen, mobile screen you are looking at right now is luminous but the page of your book is a non-luminous object, which is why you need a light on to read it.
Which statement about metals and nonmetals is correct? (1 point)
O Metals and nonmetals can both be found in any column of the periodic table.
O Most metals are a solid under normal conditions, and most nonmetals are a liquid.
O Metals tend to be poor conductors of electricity, while nonmetals are strong conductors of electricity.
O Metals can be hammered into thin sheets, and nonmetals are brittle
Answer:
The answer is the 4th one
The statement about metals and nonmetals that is correct is: "The Metals can be hammered into thin sheets, and nonmetals are brittle."
Metals are found mostly towards the left hand side of the periodic table. Non-metal character increases as you move towards the right hand side of the table.
One common property of metals is that they are malleable; this means that they can be hammered into sheets while a common property of nonmetals is that most of them are brittle.
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Measurements of the heights of various plants in an experiment are called
Answer:
Option 1 Data
Answer:
data
Explanation:
that is the answer
please 5 stars
What is the molar mass of C3H8O2? (Round to three significant figures)
Answer:
The molar mass of [tex]C_3H_8O_2[/tex] (rounded to three significant figures) is 76.1 amu.
Step-by-step explanation:
Hey there!
To answer this question, you will need access to a periodic table. You need to know the atomic masses of carbon (C), hydrogen (H), and oxygen (O) in order to answer this question. With that out of the way, let's begin!
We have a chemical formula: [tex]C_3H_8O_2[/tex].
The letters are element symbols, which are basically the code for an element. Think of it as an abbreviation or something similar to an ID.The subscripts (numbers) help us identify how many atoms of each element are included in the substance.The first thing we should do is locate C, H, and O on a periodic table and figure out the atomic masses for each element. This will help us determine the total molar mass of the substance.
Determining the Atomic Mass of CIf we locate C on a periodic table, we see that its atomic mass is roughly 12.01 amu (atomic mass units). Then, we have a subscript of 3, so we simply multiply the subscript by the given atomic mass in order to find the atomic mass of the three atoms of carbon.
[tex]3 \times 12.01 = 36.03 \text{ amu}[/tex]
This means that C accounts for 36.03 amu of the molar mass of the substance.
Determining the Atomic Mass of HUsing the same principle as before, we want to find the atomic mass of one atom of H. This is 1.008, so we will multiply 1.008 by the eight atoms (pay attention to the subscript) in order to find the atomic mass of hydrogen in the substance.
[tex]8 \times 1.008 = 8.064 \text{ amu}[/tex]
This means that H accounts for 8.064 amu of the molar mass of the substance.
* An important note to add is that we should never round our values until the end of the problem so we make sure to get as close as possible (this is why you learn about accuracy and precision in a chemistry class).
Determining the Atomic Mass of OFinally, we want to find the atomic mass of O in the substance, so we'll use the same method as before and locate the atomic mass of one atom of oxygen. We find that this is 15.999, which would definitely round to 16.00, but remember the rules for rounding in chemistry in order to be as accurate as possible. Since our subscript is 2, we know that there are two oxygen atoms, so we will multiply the atomic mass of oxygen by 2.
[tex]2 \times 15.999 = 31.998 \text{ amu}[/tex]
This means that O accounts for 31.998 amu of the molar mass of the substance.
Summation of the Determined Atomic MassesAfter you have determined the atomic masses of the atoms in the chemical substance, you have to add these together. This is performed with simple addition.
C = 36.03 amuH = 8.064 amuO = 31.998 amuNow, let's add these together.
[tex]36.03 \text{ amu} + 8.064 \text{ amu} + 31.998 \text{ amu} = 76.092 \text{ amu}[/tex]
Therefore, the total atomic mass is 76.092 amu.
Rounding to Meet Significant Figures RequirementsSignificant figures are used to determine the accuracy of a problem. A basic rule is to use scientific notation to determine how to meet the significant figure request. Since we are rounding to three significant figures, we want to make sure these three figures are significant. There are three basic rules to remember when computing significant figures:
Any zeroes to the left of the first non-zero number (ex: 0.0981) are insignificant.Any zeroes "trapped" in between other non-zero numbers (ex: 9.81075) are significant.Any zeroes to the right of the last non-zero number (ex: 5900) are significant ONLY IF they are added after a decimal point and included in the measurement (ex: 5900.)Therefore, since we need three significant figures, we have to round our value first and then determine the appropriate number of significant figures.
76.092 will round to 76.09 first, and then round to 76.1. We cannot use 76.09 since there is a trapped zero, which is considered significant.We must use 76.1 since there are three significant figures in the value.Final AnswerSince we have determined that 76.1 fits our requirements for three significant figures, we can safely determine that the molar mass of [tex]C_3H_8O_2[/tex], as determined, is 76.1 amu.
= 3 × Mass of C + 8 × Mass of H + 2 × Mass of O
= (3 × 12.01 + 8 × 1.008 + 2 × 15.999) g/mol
= (36.03 + 8.064 + 31.998) g/mol
= 76.092 g/mol
Answer:
76.092 g/mol
Hope you could get an idea from here.
Doubt clarification - use comment section.
Which of the following statements correctly explains why the excretory system is different from the digestive system? (1 point)
The excretory system is different from the digestive system because it removes waste from the body by filtering water, which
includes mostly the by-products of metabolism.
The excretory system is different from the digestive system because it removes waste from the body by filtering urine, which
includes mostly the by-products of metabolism
The excretory system is different from the digestive system because it removes waste from the body by filtering food, which
includes mostly the by-products of metabolism. filtering food
SS
2
The excretory system is different from the digestive system because it removes waste from the body by filtering blood, which
o
includes mostly the by-products of metabolism
U.
Hey
Answer:
The excretory system removes waste from the body. remove waste from the blood. The digestive system breaks down the food you eat into nutrients that provide energy and building materials for cells. The digestive and excretory sytems work together to process the food that you eat.
Which equation represents a decomposition reaction?
O 4P +502 → 2P205
O H2SO4 + 2NaOH → Na2SO4 + 2H2O
O 2C8H18 + 2502 → 16CO2 + 18H2O
O 6NaNO3 → 6NaNO2 + 302
There are various type of chemical reactions in chemistry like combination reaction , displacement reaction. One of these is the decomposition reaction. The correct option is option D.
What is decomposition reaction?Decomposition reaction is the one in which molecules breaks down in its constituent in presence of energy. Energy can be in any form, it can be light energy , heat energy.
Decomposition of water is done by providing electricity and the reaction is called electrolysis. Lysis means to break. To give decomposition reaction molecule must have more than one element.
The fourth reaction describe a decomposition reaction (NaNO3 decomposed to become NaNO2 and O2). First and third reaction are considered combustion reaction (reacting with oxygen). Second reaction is acid-base reaction.
Therefore, the correct option is option D.
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I’m having trouble on problem number 5. and I can’t find the answer, and I could really use some help.
question : what are isotopes
Answer:
Isotopes are versions of the same element. They have the same number of protons and electrons as the element but different mass numbers and number of neutrons.
Explanation:
one of two or more species of atoms of a chemical element with the same atomic number and position in the periodic table.
True or false: animals use photosynthesis to make food
What is the functional group of a carboxylic acid?
A. Carbon double bonded to oxygen and a hydroxyl group (OH).
B. Carbon bonded to a hydroxyl group (OH).
C
C. Carbon bonded to a nitrogen group.
D. Carbon double bonded to an oxygen and a hydrogen.
Answer:
A. Carbon double bonded to oxygen and a hydroxyl group (OH).
(Forgot to ask this question last time)
Which is true about molecules?
A. A molecule is two or more atoms joined
together.
B. A molecule is two or more protons joined
together.
C. A molecule is two or more neutrons bonded
together.
Answer:
A is the correct answer.
FeS + ….HNO3 …….……..+ ….H2SO4 + ….NO + ……….
Answer:
hey it's mistake in the question please check it
Which is most useful in classifying stars? (1 point)
A. knowing the movements of a star
B. knowing the size of a star
C. knowing the apparent magnitude of a star
D. knowing the color and brightness of a star
Answer:
B. Knowing the color and brightness of a star
Explanation:
Does an astronaut have more mass on earth then space? why or why not?
Answer:
No
Explanation:
No, his mass remains the same no matter where he is in the universe.
But then again the moon has less gravitational pull, therefore your weight and mass will be smaller in space and on the moon than on earth
I hope this was helpful! ;)
What are the periods and epochs of the Cenozoic era?
Please help!
Answer:
The Cenozoic Era is generally divided into three periods: the Paleogene (66 million to 23 million years ago), the Neogene (23 million to 2.6 million years ago), and the Quaternary (2.6 million years ago to the present); however, the era has been traditionally divided into the Tertiary and Quaternary periods.
Can I please have help on a Timer
Answer:
cell
tissue
organ
organ system
Explanation:
the cell is the smallest
a tissue looks like a unit
an organ is multiple units
organ systems are the full body
The amount of energy required to separate 1 mole of ions in a crystalline solid into separate gaseous ions is called _____ energy. This energy provides a measure of the strength of a(n) _____ bond, since the stronger the bond, the _____ the amount of energy required to break it.
Answer: A) Are you asking for the production of "ions" from a solid? Or are you asking for the formation of gases. For gases, this is called "energy of vaporization."
B) "Lattice," I am guessing.
C) Greater
Explanation: Most molecules enjoy their existance as solids (not all) due to the intermolecular forces that attract the molecules to each other. These are largely hydrogen and ionic bonds. Hydrophobic compounds don't always share this enthusiam to stick together. Gasoline is happy to leave it's relatives behind and it's Up, Up, and Away.
