Answer:
Explanation:
In Pre-AP Chemistry, the development of models to explain their macroscopic observations is a primary means through which students develop an understanding of the molecular world.
You will be forced to think and apply concepts to new situations, and even derive your own theories from application. This is excellent preparation for the higher levels of thinking required in college.
Chemistry, the science that deals with the properties, composition, and structure of substances (defined as elements and compounds), the transformations they undergo, and the energy that is released or absorbed during these processes.
how does an electron emit light?
Answer:
by moving between defined energy levels
If 0.42 mole of helium occupies 9.9 L, how
many moles must be added to inflate the
balloon to 17.0 L?
0.301 moles
Further explanationAvogadro's hypothesis:
In the same T,P and V, the gas contains the same number of molecules
So the ratio of gas volume will be equal to the ratio of gas moles
Given
n₁=initial mol of Helium : 0.42
V₁=initial volume : 9.9 L
V₂=final volume : 17 L
Required
number of moles added
Analysis
Use formula :
[tex]\tt \dfrac{V_1}{n_1}=\dfrac{V_2}{n_2}[/tex]
Solution
[tex]\tt n_2=\dfrac{n_1\times V_2}{V_1}\\\\n_2=\dfrac{0.42\times 17}{9.9}\\\\n_2=0.721~moles[/tex]
moles added :
0.721 - 0.42 =0.301 moles
Paraphrase
0.301 moles must be added to inflate the balloon to 17.0 L
Fill in the blanks. A person would weight more on Neptune than on planet blank
because
blank
A person would weigh more on Neptune than on planet earth because the gravitational field strength is stronger on Neptune.
A person would weight more on Neptune than on planet earth because the gravitational force in neptune is more.
What is gravitational force?Gravitational forces is a kind of attraction force which is present between two objects of masses.
Gravitational force on the neptune planet is more as compared to the gravitational force on the earth. So the mass of any object present in the neptune is more than the earth.
Hence a person would weight more on Neptune than on planet earth because gravitatinal force in neptune is more.
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Determine the number of moles in 5.25x1024 formula units if lead (IV) oxide.
Answer:
8.72 mol PbO₂
General Formulas and Concepts:
Chemistry - Atomic Structure
Using Dimensional AnalysisAvogadro's Number - 6.022 × 10²³ atoms, molecules, formula units, etc.Explanation:
Step 1: Define
5.25 × 10²⁴ formula units PbO₂
Step 2: Identify Conversions
Avogadro's Number
Step 3: Convert
[tex]5.25 \cdot 10^{24} \ formula \ units \ PbO_2(\frac{1 \ mol \ PbO_2}{6.022 \cdot 10^{23} \ formula \ units \ PbO_2} )[/tex] = 8.71803 mol PbO₂
Step 4: Check
We are given 3 sig figs. Follow sig fig rules and round.
8.71803 mol PbO₂ ≈ 8.72 mol PbO₂
12) Which model of the atom is thought to be true?
a. Protons, electrons, and neutrons are evenly distributed throughout the volume of
the atom.
b. The nucleus is made of protons, electrons, and neutrons.
c. Electrons are distributed around the nucleus and occupy almost all the volume of
the atom.
d. The nucleus is made of electrons and protons.
Answer:
B
Explanation:
The neucles is surrounded by electrons. Electrons occupy most of the volume of the atom.
Atomic Model:
Atoms are the smallest unit of elements, which form bonds with others. In an atom, electrons revolve around the nucleus.
The nucleus is composed of positively charged protons and neutrons. The nucleus occupies a very small part of the atom.
Electrons are negatively charged particles, they are found around the nucleus and occupy most of the part of the atom.
Therefore, The neucles is surrounded by electrons. Electrons occupy most of the volume of the atom.
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2. Why is soil considered limited?
Answer: he natural area of productive soils is limited – it is under increasing pressure of intensification and competing uses for cropping, forestry, pasture / rangeland and urbanization, and to satisfy demands of the growing population for food and energy production and raw materials extraction
What type of reaction will occur with the following reactants?
CaS + NaCl -->
A) double replacement
B) decomposition
C) synthesis
D) single replacement
Answer:
A) double replacement
Explanation:
Chemical equation:
NaCl +CaS → Na₂S + CaCl₂
Balanced chemical equation:
2NaCl +CaS → Na₂S + CaCl₂
The given reaction is double replacement reaction in which cation and anions of each reactant exchange with each other.
Double replacement:
It is the reaction in which two compound exchange their ions and form new compounds.
AB + CD → AD +CB
Other options are incorrect because,
Synthesis reaction:
It is the reaction in which two or more simple substance react to give one or more complex product.
AB → A + B
Single replacement:
It is the reaction in which one elements replace the other element in compound.
AB + C → AC + B
Decomposition reaction:
It is the reaction in which one reactant is break down into two or more product.
AB → A + B
____ Ca3(PO4)2(s) + ____ H3PO4(l) → ____ Ca(H2PO4)2(s) When the equation above is balanced and all coefficients are reduced to lowest whole-number terms, what is the coefficient for H3PO4(l)
The equation can be balanced using suitable integers multiplied either side and can be written as follows:
[tex]\rm Ca_{3} (PO_{4})_{2} + 4 H_{3}PO_{4} \rightarrow 3 Ca (H_{2}PO_{4})_{2}[/tex]
Thus the coefficient of H₃PO₄ is 4.
What is balanced reaction?A balanced chemical equation of a reaction represents all the reactants and products in the perfect stoichiometric ratios where, the number of each element have to be equal in both sides.
The given reaction is an example of combination reaction. The equation can be balanced by equating the number of calcium in the product side by multiplying with 3 and then making the phosphate group also balanced by multiplying by 4 with H₃PO₄.
Thus, the balanced chemical equation written above contains 3 calcium on both side and equal number of phosphate group (6) as well as hydrogens on both side where, the coefficient of H₃PO₄ is 4
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Solid carbon dioxide (CO2), also known as dry
ice, changes into a gas at room temperature. An
image of this change can be seen below.
Is this an example of a physical change? Why
or why not?
Answer:
yes
Explanation:
yes because the ice changes forms physically and can be changed back. not 100% sure tho
Answer:
shiii ion even know like i cant even tell u tha
Explanation:
bro 2 of my bruddas got locked up 2 days ago one of em got shot before the cops took him
All of these are examples of compounds except
Answer:
Add a picture please! or give answer choices
Explanation:
Answer:
theres no examples
Explanation:
i can answer if you add examples
What happens to alpha particles as they get closer to the gold nucleus?
Answer:
Initially the alpha particle has only kinetic energy EK. As it approaches the gold nucleus it suffers repulsion by the 79 protons within that nucleus. Its kinetic energy changes into electric potential energy EP.
How many moles are there in 32.4 grams of Na
According to the mole concept, there are 1.4087 moles in 32.4 grams of sodium.
What is a mole?Mole is defined as the unit of amount of substance . It is the quantity measure of amount of substance of how many elementary particles are present in a given substance.
It is defined as exactly 6.022×10²³ elementary entities. The elementary entity can be a molecule, atom ion depending on the type of substance. Amount of elementary entities in a mole is called as Avogadro's number.
It is widely used in chemistry as a suitable way for expressing amounts of reactants and products.For the practical purposes, mass of one mole of compound in grams is approximately equal to mass of one molecule of compound measured in Daltons. Molar mass has units of gram per mole . In case of molecules, where molar mass in grams present in one mole of atoms is its atomic mass.
Number of moles in this case is obtained by dividing mass by molar mass that is, 32.4/23=1.4087 moles.
Thus, there are 1.4087 moles in 32.4 g of sodium.
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Help plz 15 pointsss
TRUE or FALSE: The rock closest to the ridge is newer and younger than the older rock
further away from the ridge.
Answer:true
Explanation:
hhhhhhhhhheeelp !!! give 20 pintos
Answer:
you can run out of money the supplier could run out or they could stop making the renewable.
Explanation:
Agree or disagree
one rotation of the earth occurs everyday or 24 hours
Answer:
Agree
Explanation:
The rotation of earth happens about once every 24 hours.
What is the hybridization of the carbon in the HCN molecule?
What goes in photosynthesis and what comes out of photosynthesis?
Answer:
Carbon dioxide goes in and oxogen comes out
P.S. Sunlight needed for this process to work
Explanation:
>>>>>>>>>>>>>>>>>>>>>>>
LETS JUST END THIS ARGUMENT NOW!!!!
WHO BELIEVES THAT CEREAL ALWAYS GOES FIRST IN THE BOWL!!!!!!!!!!!??????????
You are crazy if you add the milk first!!!
YOU MONSTERSSS
Yuh im jus bord
Answer:
cereal then milk
Explanation:
Answer:
Milk first as always and always will be
Explanation:
Get flexed on ;)
What is the total number of electrons in an atom of an element with an atomic number of 18 and a mass number
of 402
a. 58
c. 22
b. 18
d. 40
Answer:
18
Explanation:
Bats have oversized ears, which help the bats use sound waves to detect the motion of their prey. Which example of the characteristics of life is most similar?
Answer:
option B = A rat hides in its hole when it sees an approaching predator.
Explanation:
In order for any organisms, whether plants or animals to be able to keep being alive they have to develop a/some functions or abilities which is going to aid in their battle battle for survival, this concept is known as the Adaptive features of organisms.
From the question above, it can be seen that the oversized ears in bats is an adaptive features for them to get their food: as it helps them to use sound waves to detect the motion of their prey.
Unlike the bats, the rats adaptive features is to have a good running legs. This will help them to avoid getting eating by predators.
Answer:just saying he is correct
Explanation:
Elements in a ___ on the Period Table of Elements have similar chemical characteristics and properties.
two negative charges are placed near each other. what happens between the charges
Answer:
repulsion
Explanation:
Answer:
Explanation:
In contrast to the attractive force between two objects with opposite charges, two objects that are of like charge will repel each other. ... Similarly, a negatively charged object will exert a repulsive force upon a second negatively charged object. Objects with like charge repel each other.
You are making lemonade and the calls for 6 cups Lemon juice (L), 3 Cups of sugar (S) and 5 cups of water (W) to make 12 Cups of Lemonade (LA): your formula is:
6 L + 3 S + 5 W = 12 LA
You are given 9 cups of lemon juice (L), 8 cups of sugar (S) and unlimited water (W).
How many cups of lemonade can you make?
1. 9
2. 12
3. 18
4. 32
Answer:
18 Cups
Submitted the assignment
Explanation:
In what way is Model A better than Model B? Model A shows the types of elements in the compound, but Model B does not. Model A shows the total number of atoms in the molecule, but Model B does not. Model A shows the three-dimensional shape of the molecule, but Model B does not. Model A shows the number of atoms of each element in the molecule, but Model B does no
Answer:the answer is c babes
Explanation:
I hope I could help y’all
Have a nice day
Or whatever day u want LMA0 it’s not up to me. Ight peace loves
Model A is better than Model B as Model A shows the three-dimensional shape of the molecule, but Model B does not. The correct option is c.
What are molecules?The smallest particle of a substance possesses all of its physical and chemical properties. One or more atoms make up a molecule.
Knowing the molecular weights of the molecules allows us to calculate their sizes. The molecular weight of a molecule is the sum of the atomic weights of the atoms in the molecule.
The relative atomic mass of particles determines their size. Particles with a higher relative atomic mass weigh more than particles with a lower relative atomic mass. Larger atoms have heavier iotas and a larger relative atomic mass.
Therefore, the correct option is c, Model A shows the three-dimensional shape of the molecule, but Model B does not.
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In a group of rats, some individuals have a normal-sized body and others have a dwarf body. In this group, the gene for the body size trait has two alleles. The allele B is for a normal-sized body, and the alleles is for a dwarf body
Answer:
n a group of rats, some individuals have a normal-sized body and others have a dwarf body. In this group, the gene for the body size trait has two alleles. The allele for a normal-sized body (B) is dominant over the allele for a dwarf body (b).
Squeaky, a rat from this group, has a dwarf body.
Based on Squeaky's phenotype for the body size trait, which of the following could be Squeaky's genotype for the body size gene?
Explanation: can someone pls help?
THIRTY POINTS I NEED HELP HURRY What is the volume of the cone?
Answer:
V=πr2h 3
Explanation: I would give more but need more i information
Answer:there u go
Explanation:The volume V of a cone with radius r is one-third the area of the base B times the height h . Note : The formula for the volume of an oblique cone is the same as that of a right one. ... If the heights of a cone and a cylinder are equal, then the volume of the cylinder is three times as much as the volume of a cone
PLEASE HELP ASAP I NEED THIS THANK YOU SOO MUCH
which of the two chemical equations follow the Law of Conservation of Mass
Equation A: Zn +2HCl —> ZnCl2+ 2H2
Equation B: Zn +2HCl —> ZnCl2 + H2
Equation A: Zn +2HCl —> ZnCl2+ 2H2
True or False: Sulfur by itself isn't too bad, it's when it reacts with other elements that it can become dangerous
Answer:sulfer by itself is not pleasant and it can be dangerous by itself but in large amounts.
Explanation:
Answer:
True.
Explanation:
Also did you know that it is combined with chlorine that it becomes salt? Cool right? Two deadly things combining to become a condiment
Can someone define these for me
Answer:
These are all in order....
Explanation:
- closed system usually absorbs thermal energy from its surroundings, which is heat transfer into the system
- a solute is a substance dissolved in another substance, known as a solvent
- A solvent is a substance that dissolves a solute, resulting in a solution. A solvent is usually a liquid but can also be a solid, a gas, or a supercritical fluid
- a liquid mixture in which the minor component (the solute) is uniformly distributed within the major component (the solvent)
- a nuclear reaction in which a heavy nucleus splits spontaneously or on impact with another particle, with the release of energy
- a nuclear reaction in which atomic nuclei of low atomic number fuse to form a heavier nucleus with the release of energy.
- Half-life is the time required for a quantity to reduce to half of its initial value
- the determination of the age or date of organic matter from the relative proportions of the carbon isotopes carbon-12 and carbon-14 that it contains. The ratio between them changes as radioactive carbon-14 decays and is not replaced by exchange with the atmosphere.
- any system closed to all transfers of matter and energy, the mass of the system must remain constant over time, as the system's mass cannot change, so quantity can neither be added nor be removed