C9H8O. .....................
What is an allotrope?
a) The same atom with a different number of neutrons
b) A radioactive substance
c) An alternative form of an element
d) Diamond
If you were an astrobiologist, what would you do to search for life?
Astrobiologist means someone who studies the possibilities of life beyond earth. what would YOU do to search for life? They're asking for your opinion :)
Let’s Apply B
Directions: Identify the stages in the life cycle of a frog that is being described.
Give the correct answer that is being described.
NONSENSE = REPORT
PLEASE PA SAGOT !!!!!
Answer:
b a c a b
Explanation:
give explanation ~~
Why are cloudy nights warmer than clear nights?
which option can be classified as a pure substance
A. solution
B. compound
C. homogeneous mixture
D. heterogeneous mixture
Answer:
B. compound
Explanation:
A pure substance can be an element, which consists of only one type of atom and cannot be broken down by a chemical change, or a compound, which consists of two or more types of atoms.
in sequence from highest to lowest temperature: A) Lithosphere; B) Mantle; C) Core
What is a net ionic equation?
Examine the model of the different states of matter. Select ALL of the statements that accurately describe the particles in differing states. A) Gases contain less particles. B) Gases have the greatest kinetic energy. C) Energy is removed in the change from a liquid to a gas. D) Energy is added to change from a solid to a liquid state. E) In a solid, particles are so closely packed that they can only vibrate in place.
The statements which accurately describe the particles in differing states include:
Gases have the greatest kinetic energy.Energy is added to change from a solid to a liquid state. In a solid, particles are so closely packed that they can only vibrate in place.Gases have the greatest kinetic energy which explains why its particles
move very rapidly and randomly when compared to other states of matter.
Conversion from solid to liquid or liquid to gas requires more energy being
added.
The particles in solids are tightly packed with very restricted movements
which is why they are able to vibrate at a place.
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how many moles are there in 1 mole of argon?
the atomic mass of argon is 39.948. That means that one mole of argon weighs 39.948 grams (39.948 g/mol).
Calculating Heat during Phase Changes
question below in photo :)
Answer:
Q1= 9.42
Q2= 227 KJ
Q3= 31.4 KJ
Qt=269 KJ
Explanation:
First you have to find the heat needed to make ice at a temperature of -45 C to pass to a temperature of 0 C.
You're given the formula so all you have to do is replace by the data you're given (remember to make the Celsius, Kelvin by adding 273.15 to the Celsius since the magnitudes of temperature they're giving you in the constants are the Kelvin)
Q1= (2.093 J/gxK)(100 g)(45 K)
Q1=9418.5 J
Q1=9.4185 KJ≈9.42 Kj(you're asked to give your answer in KJ)
You know have to find the energy needed to liquify the ice, in other words you need to use the enthalpy of fusion to determine the energy that's being used, and since you have 100 grams of water, you only need to find the number of moles present in 100 grams of water by dividing the number of grams by the molar mass of water (18 g/mol) and then replace in the equation.
Q2=(5.56 mol)(40.7 KJ/mol)
Q2=227 KJ
You know have to find the energy needed to raise the temperature of water from 0 C to 75 C. You do the same thing as you did in the first step:
Q3=(4.184 J/gxK)(100 g/)(75K)
Q3=31380 J
Q3=31.38 KJ≈31.4 KJ
For the final step, you only add the Qs of each step:
9.42KJ+227KJ+31.4KJ= 267.82 KJ ≈ 267.8 KJ
Why do you use these procedures?
Well, you could simply have made a unique equation at first sight that involved the changes of temperature from -45 C to 75 C, but you have a phase change in the middle. Phase change keep temperature constant but they require heat from the surroundings in order to, in the case of ice, break the bonds that keep the molecules tight together.
This heat required from the surroundings is the Enthalpy of phase change, in this case enthalpy of fusion.
4. Which of the following statements accurately compares the wavelengths of the waves shown below?
A) wave 1 has a smaller wavelength than wave 2
B) wave 1 has a larger wavelength than wave 2
C) wave 2 has a larger wavelength than wave 1
D) wave 1 and wave 2 have the same wavelength
Answer:
B. wave 1 has a larger wavelength than wave 2
Wave 1 has larger wavelength than wave 2. Hence, option B is correct.
What is Wavelength?Wavelength is defined as "the difference between two successive crests and troughs of the wave. The wavelength described the how long wave is. It is measure in the direction of wave.
Wavelength is usually denoted by the Greek letter ( λ ).
Wavelength is equal to the speed ( V ) of wave train to divided by frequency ( F ). It is given as,
λ = V ÷ F
Here,
λ = wavelength
V = speed
F = frequency
The distance between one crests (top) to another crests is a Wavelength. Alternately the distance between one troughs (bottom) to another troughs is wavelength.
The distance between two crests in wave 1 is more comparatively wave 2 so , wave 1 will have larger wavelength than wave 2.
Therefore, wavelength is used for measuring the radiation.
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Lead has an atomic number of 82. Which statement describes all neutral atoms and ions of lead?
Neutral atoms of lead must have 82 electrons. Ions must have 82 electrons, as well.
Neutral atoms of lead must have 82 neutrons, but ions can have more or fewer.
Neutral atoms of lead must have 82 protons. Ions must have 82 protons, as well.
Neutral atoms of lead must have 82 protons, but ions can have more or fewer.
The neutral atom of lead must have 82 protons while ions can have b or less than 82.
The atomic number of an element is the number of protons in the nucleus of the element.
Also, for neutral atoms, the number of protons equals the number of electrons.
In ionic form, the number of protons/electrons of an atom may vary and be different from that of the neutral form.
Positive charges mean that the ion has less proton than its neutral version while negative charges mean that it has more electrons than its neutral version.
Thus, the neutral atom of lead will contain an equal number of protons as the electrons while its ionic form can have more or less than 82 protons.
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Which of the following compounds has the general formula X3Y2?Which of the following compounds has the general formula X3Y2?
There are no above options to choose from so I am giving an example of a X3Y2 formula which is Magnesium nitride, the formula is Mg3N2.
Summarize: Complete the following statements:
A. 1 mole of any element contains 6.0221 x 1023 _____
B. 1 mole of any compound contains 6.0221 x 1023 ______
Answer:
Explanation:
Taking into account the definition of Avogadro's Number, the correct answers are:
1 mole of any element contains 6.023×10²³ atoms
1 mole of any compound contains 6.023×10²³ molecules
You have to know that Avogadro's Number or Avogadro's Constant is called the number of particles that make up a substance (usually atoms or molecules) and that can be found in the amount of one mole of said substance. Its value is 6.023×10²³ particles per mole.
Avogadro's number represents a quantity without an associated physical dimension, so it is considered a pure number that allows describing a physical characteristic without an explicit dimension or unit of expression.
Avogadro's number applies to any substance, because the number of elementary units in a mole of a substance is, by definition, a constant that does not depend on the material or the type of particle considered.
So, in this case, the correct answers are:
1 mole of any element contains 6.023×10²³ atoms
1 mole of any compound contains 6.023×10²³ molecules
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which best explains why water dissolves most salts?
Answer:
where are the answers?
Explanation:
Do you think the amount of fat will affect its melting point?
I need to right a journal entry for school but i don't know what to put Write a journal entry from the perspective of a particle of light,
called a photon. Your story should follow the photon as it
travels from a star in the Milky Way that is 25 light years away
from Earth, all the way to the eye of a young person gazing up
at the night sky through their bedroom window. Compose your
entry in complete sentences.
it is for my 5 grad sicenc
Answer:
here you go
Explanation:
someone help me on this but i still got a hundred
A container that can't expand, may explode from the ________ in pressure.
which pair of atoms constitutes a pair of isotopes of the same element?
Answer:
element with same number of protons but different number of neutrons
brainliest plzzzzz
Which of the following is not an alteration of a document?
additions
obliteration
erasure
O all of these answers
charring
None of these answers
ill give brainley
Use this oxidation-reduction reaction to answer questions about half-reactions:
Upper m g plus 2 upper H upper C l right arrow upper M g upper C l subscript 2 plus upper H subscript 2.
Classify these half-reactions by typing in “O” for “oxidation half-reaction,” “R” for “reduction half- reaction,” and “N” for “neither.”
Answer:
For those who need it, the answers are N, O, R
Explanation:
To solve such this we must know the concept of redox reaction. Therefore, the given reaction is an oxidation and reduction reaction. The oxidation reaction is Mg [tex]\rightarrow[/tex] MgCl[tex]_2[/tex] and reduction reaction is HCl [tex]\rightarrow[/tex] H[tex]_2[/tex] .
What is chemical reaction?Chemical reaction is a process in which two or more than two molecules collide in right orientation and energy to form a new chemical compound. The mass of the overall reaction should be conserved. There are so many types of chemical reaction reaction like combination reaction, double displacement reaction.
Redox reaction is a chemical reaction where oxidation and reduction takes place simultaneously. Oxidation is loss of electrons and reduction is gain of electrons. The electron transfer from oxidant to reductant.
Mg + 2HCl [tex]\rightarrow[/tex] MgCl[tex]_2[/tex] + H[tex]_2[/tex]
Mg [tex]\rightarrow[/tex] MgCl[tex]_2[/tex] O
HCl [tex]\rightarrow[/tex] H[tex]_2[/tex] R
Therefore, the given reaction is an oxidation and reduction reaction.
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Distance traveled over a period of time is?
Answer:
AVERAGE speed is the total distance traveled divided by the elapsed time.
Sasha did an experiment to study the solubility of two substances. She poured 100 mL of water at 20°C into each of two beakers labeled A and B She put 50 g of
Substance A in the beaker labeled A and 50 g of Substance B in the beaker labeled B. The solution in both beakers was stirred for 1 minute. The amount of substance
left undissolved in the beakers was weighed. The experiment was repeated for different temperatures of water and the observations were recorded as shown.
Experimental Observations
Mass of Undissolved Substance at Different Temperatures (gram)
20°C
40 °C
60°C
80 °C
Substance
А
12
11
9
8 8
B
45
40
34
31
Part 1: Which substance has a higher solubility?
Part 2: Explain your answer for Part 1
Answer:
Answer temperatures gram is correct because there is more of a mass of numbers and the numbers are higher. (don't really know this subject, just guessing, hope this helped.)
The substance A has higher solubility then substance B because the higher the temperature the easier the substance will dissolve.
What is solubility?The word solubility is defined as the ability of a substance, the solute, to form a solution with another substance, the solvent.
It can also be defined as a property that allow sugar molecule to dissolve.
It can be defined as at a given temperature, the amount of solute that can dissolve in a given amount of solvent.
In this reaction, increasing the pressure and temperature results in increased solubility. An increase in pressure causes more gas particles to enter the liquid, lowering the partial pressure.
For exothermic reaction the temperature increases with decrease in solubility and for endothermic reaction the temperature decreases with increase in solubility.
Thus, the substance A has higher solubility then substance B because the higher the temperature the easier the substance will dissolve.
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15 points who can solve help plsss now
Answer:
C. Al and O2
Explanation:
The reactants are the elements or compounds that is becoming the result
So Al and O2
Hope this helps!
Please help me find the answer to this question
Answer:
A tumor
Explanation:
Answer:
It's Cancer
Explanation:
I did this before.
Which statement about the Periodic Table is correct?
A Elements are arranged in order of decreasing proton number.
B Group number is the number of electron shells in atoms of the elements in the group.
C Group numbers can be used to predict the charges of ions.
D Metallic character increases left to right across a period.
answer :c
explanation :
group numbers can be used to determine the number of electrons in the outer most shell thus if the group numbers are above four then the elemnts are negative ions if less than four then posetive
Select from the unit conversion factor options below to determine the mass in grams of 1.204 × 1024 atoms of carbon.
1 mol C/ 6.02 x 1023 atoms C, 6.02 x 1023 atoms C / 1 mol C
12 g C / 1 mol, 1 mol / 12 g C
a
12040 g
b
24 g
c
204 g
d
1.99 g
Answer:
option a is the answer
Explanation:
bye bye
the atomic number of four elements p,q,r,s are 6,8,10 and 12 respectively. the two elements which can bond ionically are:
Answer:
The atomic numbers of four elements A, B, C, and D are 6,8,10, and 12 respectively. The two elements which can react to form ionic bonds (or ionic compounds) are B (8= 2,6) and D (12 =2,8,2). So D donates its two electrons to B to fulfill their octet.
Explanation:
6.23 X 10^6 KL + 5.34 × 10^6 kL
the high electrical conductivity of metals is primarily due to
High conductivity of metals is caused by electrons that are free to move through the lattice.
hope this helps!