Answer:
Explanation:
Q1) as we know that moles=given mass/molar mass
mass of 5 moles of Mg is
mass =moles*molar mass
mass=5*24
mass=120 g
mass of 5 moles of CaCO3 is
mass= moles*molar mass
mass=5*100=500
Q2) number of atoms in 10 g Na
first we need number of moles of sodium
moles =mass/molar mass
moles=10/23=0.43
now we know that moles=number of atoms /avogadro number
for number of atom the formula become
number of atom=moles*avogadro number
number of atom=0.43*6.023*10^23=2.6*10^23
Q3)number of molecule in 10 g of NaCl
again we need number of moles of NaCl
moles=given mass/molar mass
moles=10/58.5=0.17
now number of molecules=moles*avogadro number
number of molecules=0.17*6.023*10^23=1.02*10^23
Q4) avogadro number is the number of particles(atoms,molecules,ions) present in one mole of a substance its value is 6.023*10^23
Q5)Number of atoms in 4g of oxygen
again we need number of moles of oxygen
moles=mass/molar mass
moles=4/16=0.25
now number of atoms=moles*avogadro number
number of atoms=0.25*6.023*10^23 =1.5*10^23
The density of aluminum is 2.70 g/cm'. If the volume of a piece of aluminum is 90.4 cm', what is
the mass of the aluminum?
Answer:
33.4814814815
Explanation:
90.4/2.70
What is the name of alkane having seven carbons atoms in the chain????
Answer:
n-heptane is your answer
Answer:
Hence, C5H12 is called pentane, C6H14 is called hexane, C7H16 is called heptane and so forth. Straight-chain alkanes are sometimes indicated by the prefix n- (for normal) to distinguish them from branched-chain alkanes having the same number of carbon atoms.
Explanation:
Question 2
Which phrase best describes an apple?
O homogeneous compound
O heterogeneous substance
O homogeneous mixture
O heterogeneous mixture
Answer:
an apple is best described as a heterogeneous mixture.
The phrase that best describes an apple is heterogenous mixture because it is made up of a different materials.
What is a mixture?A mixture is combination of different components that can be uniform or dispersed and homogenous or heterogenous. A homogenous mixture is the one in which the two or more components are dissolved together to form only one phase.
A heterogenous mixture is composed different phases with uniform or irregular arrangement of materials. Heterogenous mixtures look like a nonseparated random particles which are clearly distinguishable by eyes.
Apple is not a compound but is a mixture made up of different components such as water, pulp, seeds, pigments etc. and each forms their own phases.
Hence, Apple can be termed as a heterogenous mixture.
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Predict the empirical formula of the ionic compound that forms from aluminum and oxygen.
A. AIO.
B. Al2O.
C. Al2O3.
D. Al3O2.
E. AlO2.
Answer:
A. AlO
Explanation:
The empirical formula of a compound is the simplest possible formula giving the ratio of atoms in a molecule of the compound.
We know that Aluminium forms [tex]Al^{3+}[/tex] and oxygen forms [tex]O^{2+}[/tex].
As such the formation of the ionic compound between a metal and non-metal results into [tex]Al_2O_3[/tex].
The empirical formula is as follows:
Element Aluminium Oxygen
% composition
by mass 26.98 16.0
mole ratio 26.98/26 16/16
= 1.04 = 1
divided by the
smallest number 1.04/1 1/1
1.04 1
The empirical formula is AlO
Imagine a friend is planning a rock-climbing trip. Write a note in the box explaining how gas exchange is affected at the top of a mountain, where air pressure is lower and there is less oxygen than at lower altitudes.
Answer:
Air is less dense on a mountaintop than at sea level.
Air pressure is lower at low altitudes.
As you climb a mountain, air pressure increases.
More force pushes on the air at the bottom of an air column.
As you descend a mountain, air molecules are closer together.
Explanation:
PLS I NEED HELP give me examples of an atom
Answer:
Neon (Ne)
Hydrogen (H)
Argon (Ar)
Iron (Fe)
Calcium (Ca)
Deuterium, an isotope of hydrogen that has one proton and one neutron.
Plutonium (Pu)
F-, a fluorine anion.
Explanation:
I got u
Flammable materials, like alcohol, should never be dispensed or used near Group of answer choices an open door. a sink. another student. an open flame.
Answer:
An open flame. Hope this helped! :)
How many values of these of these trials can be considered accurate?
Answer:
go to google
Explanation:it all ways work
What is the mass of a liquid having a
density of 1.40 g/mL and a volume of
3090 mL?
Answer:
It has a mass of 4.326 grams.
Explanation:
Describe, in terms of particle arrangement, why the substance with the smallest density and the substance with the largest density has different densities.
Explanation:
Density of a substance may be defined as the amount of mass or matter it contains in a unit space or volume of that substance. It is the quantity of the matter that a body possess or contains.
Mathematically,
density = mass / volume
Different substance shave different densities. The arrangement of molecules or atom particles in the substances makes a substance less denser or more denser than the other substance.
In liquid or gas, the molecules are loosely bound to each other and there are more empty space or void spaces in the substance. Thus this make liquid and gas less dense.
On the other hand, the molecules in solid are tightly bound and they are packed, with no or very less empty space. Therefore, solids have the largest density than the gases which have the smallest density.
Will give Brainlist!!!!!!! PLEASE HELP! Express the results of the following calculations with the correct number of significant figures: 5502.5 + 21 + 0.06
3. The ratio of an object's mass to its
is called the density of the object.
Answer:
The ratio of an object's mass to its volume is called density of an object
Explanation:
Density=mass/volume
Which of the following is an example of a chemical property?
o corrosion
o boiling point
o ability to dissolve
o melting point
Answer:
Corrosion is your answer
Answer:
▷The answer would be
▶︎corrosion
Explanation:
~corrosion~ is a natural process that converts a refined metal into a more chemically stable form such as oxide, hydroxide, or sulfide. It is the gradual destruction of materials by chemical and/or electrochemical reaction with their environment
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✭i only need 3 more brainliest then my lvl will go upp
What word starting with “J” was a period that dinosaurs existed within?
Answer:
Jurassic period
Hope this helps!
How far is it from H to G?
Which of the following is the most accurate definition of a civilization?
humans being able to communicate with each other.
humans being able to travel to other regions
the stage of humans being able to find food
the stage of human social and cultural development
Answer:
The stage of human social and cultural development.
Explanation:
Answer:
The stage of human social and cultural development.
on:
Mr.Davies has requested that you wait for 10 more minutes is that informal or formal
Answer:
Formal
Explanation:
Answer:
I think its formal because the question looks a bit fancy by using all the present perfect tense..
hope this helped you
please mark as the brainliest ( if its correct)(ㆁωㆁ)
49.2 m = _________ hm
How many calories of heat are required to raise the temperature of 1.00kg of water from 10.2 degrees Celsius to 26.8 degrees Celsius?
Answer:
Explanation:
we know that specific heat is the amount of heat required to raise the temperature of substance by one degree mathmeticaly
Q=mcΔT
ΔT=T2-T1
ΔT=26.8-10.2=16.6
C for water is 4.184
therefore
Q=1.00*4.184*16.6
Q=69.4 j
now we have to covert joule into calorie
1 calorie =4.2 j
x calorie=69.4 j/2
so 69.4 j =34.7 calorie thats why 34.7 calorie heat is required to raise the temperature of water from 10.2 to 26.8 degree celsius
The gold-foil experiment was used to discover which subatomic particle? Question 2 options: electrons protons ==> neutrons (my answer)
Answer:Proton, the gold foil experiment indicated that the nucleus has a positive charge.
What is the name of the binary molecule H2O2
Explanation:
H2O2: hydrogen peroxide.
hope it will help u ✌️
Which best explains how photosynthesis is helpful to humans? It reduces the amount of harmful rays released by the sun. It increases the levels of carbon dioxide in the air. It provides oxygen for humans to breathe. It produces proteins, which humans can eat.
Answer:
it provides oxygen for the human to breathe
Explanation:
During photosynthesis plants absorbs carbon dioxide from the atmosphere and release oxygen into the air. Hence, it increases the level of oxygen for breath.
What is photosynthesis?Photosynthesis is a biological process by which green plants produce energy and molecular oxygen in leaf by the aid of light energy. The photoactive pigments chlorophyll in green leaves absorbs light energy sufficient for this process.
The photosynthetic reaction involves combination of carbon dioxide and water to form glucose and oxygen as written below:
[tex]\rm 6H_{2}O + 6CO_{2} \rightarrow C_{6}H_{12}O_{6} + 6O_{2}[/tex].
Therefore, photosynthesis decrease the level of carbon dioxide and increase the level of oxygen in the air . Thus, plant biomass helps us to provide oxygen to breath.
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Who wrote the first modern chemical textbook?
O Antoine Lavoisier
O Dmitri Mendeleev
O Henry Moseley
O Johann Dobereiner
Answer:
Antoine Lavoisier
Explanation:
Antoine Lavoisier wrote the first modern textbook. It is the answer.
The modern chemical textbook was written by Antoine Lavoisier. The book is titled as Elementary Treaties On Chemistry.
Who is Antoine Lavoisier?Antoine Lavoisier is known as the father of modern chemistry. He contributed a lot to revolutionize chemistry. Antoine Lavoisier proposed the law of conservation of mass.
Nomenclature of chemical compounds was proposed by Antoine Lavoisier. He studied about the combustion and respiration in detail and the results are written in the book Elementary Treaties On Chemistry.
Hence, the first modern chemical textbook was written by Antoine Lavoisier.
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Use your knowledge of atomic calculations to complete the chart.
Element
Protons
Neutrons
Electrons
Atomic
Number
3
15
Atomic
Mass
7
31
35
19
28
31
P
ci
Ni
K
Ag
H
39
19
-18
47
OK
1
1
14
14
06
3
Si
w
74
1010
Ne
10
10
Answer:
For hydrogen. H
Explanation:
Atomic number is 1
Proton number is 1
Mass number is 2
Neutron number is 1
A 20 kg curling stone is sliding in a positive direction at 4 m/s. A second curling stone is sliding at the same speed but in the opposite direction. What is the kinetic energy of the two stones?
Answer:
The kinetic energy of the two stones is 320 J
Explanation:
Kinetic energy is the energy that a body possesses due to its movement. So it is the capacity or work that allows an object to go from being at rest, or still, to moving at a certain speed.
In other words, the kinetic energy of an object is that which is produced due to its motion and depends on its mass and velocity as follows:
[tex]Ec=\frac{1}{2} *m*v^{2}[/tex]
where the kinetic energy Ec is measured in joules (J), the mass m is measured in kilograms (kg) and the velocity v in meters/second (m/s).
In this case you know that a 20 kg curling stone is sliding in a positive direction at 4 m/s. So:
m= 20 kgv= 4 m/sReplacing you have:
[tex]Ec_{1} =\frac{1}{2} *20 kg*(4\frac{m}{s}) ^{2}[/tex]
Ec₁= 160 J
A second curling stone slides at the same speed but in the opposite direction. So:
m= 20 kgv= - 4 m/sReplacing you have:
[tex]Ec_{2} =\frac{1}{2} *20 kg*(-4\frac{m}{s}) ^{2}[/tex]
Ec₂= 160 J
The kinetic energy of the two stones is calculated as:
Ec= Ec₁ + Ec₂
Ec= 160 J + 160 J
Ec= 320 J
The kinetic energy of the two stones is 320 J
A hair gel is a mixture. Which of the following is true about hair gel?
A. A chemical change is required to separate its mixed components
B. A physical change can separate its mixed components.
C. It is made up of millions of units of a single type of compound.
D. It is made up of millions of atoms of a single element
Answer:
B. A physical change can separate its mixed components.
Explanation:
Atoms and molecules of different elements can come together to form a substance known as MIXTURE. A mixture comprises of several units of different elements or compounds that are not chemically joined together. This is the case of hair gel, which is a mixture i.e. it contains several compounds mixed together in an uneven ratio.
Since the components of a mixture such as the hair gel, are not joined together chemically i.e no chemical bonding or altering of chemical structure occurs between the mixture constituents, they can be separated using physical means. Physical methods of separation such as boiling, chromatography, etc.
A student performs the following experiment.
Step 1: she pours a colorless solution into a beaker that contains another colorless liquid. Yellow particles appear in the liquid.
Step 2: she lets the yellow particles settle in the beaker and then separates the colorless liquid by decantstion.
What most likely occurred in the beaker?
Answer: A chemical change in step one and a physical change in step two. ( So A) on edu
Explanation:
Answer:
A. a chemical change in step 1 and a physical change in step 2
Explanation:
Correct on Edge 2022!!!
Good luck everyone, you got this! Have a great day!
two ways
2 Describe two ways in which sodium chloride is different from chlorine. (for 7th graders)
If you dissolve 5.00 kg of methanol (CH_4O) in 2.00 m^3 of water, how many molecules of methanol per liter of water do you have? (1 kg = 1000 g; 1 m^3 = 1000 L)
Given :
Mass of methanol ( [tex]CH_3OH[/tex] ) , m = 5 kg = 5000 g .
Volume of water , [tex]V=2\ m^3=2000\ L[/tex] .
To Find :
Molecules of methanol per liter of water .
Solution :
Moles of methanol , [tex]n=\dfrac{5000}{32}=156.25\ mol[/tex] .
We know , 1 mole of a substance contains [tex]6.022\times 10^{23}\ mol^{-1}[/tex] .
So , total number of molecules :
[tex]M=156.25\times 6.022\times 10^{23}\\\\M=9.41\times 10^{25}[/tex]
Number of molecules per liter :
[tex]\dfrac{9.41\times 10^{25}}{2000}\\\\4.705\times 10^{22}[/tex]
Hence , this is the required solution .
Oil and water placed in a jar will separate. Even when
shaken and mixed, the oil still separates from the
water.
Which best describes oil and water?
Oil and water are highly soluble because they have
separate chemical properties.
Oil and water have a low solubility because they
have separate chemical properties.
Oil and water are highly soluble because they exert
different pressures
Oil and water have a low solubility because they
exert different pressures.
The answer is option B :)
According to the concept of solubility, oil and water have a low solubility because they have separate chemical properties.
What is solubility?
Solubility is defined as the ability of a substance which is basically solute to form a solution with another substance. There is an extent to which a substance is soluble in a particular solvent. This is generally measured as the concentration of a solute present in a saturated solution.
The solubility mainly depends on the composition of solute and solvent ,its pH and presence of other dissolved substance. It is also dependent on temperature and pressure which is maintained.Concept of solubility is not valid for chemical reactions which are irreversible. The dependency of solubility on various factors is due to interactions between the particles, molecule or ions.
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