The number of particles : 2.75 x 10²¹
Further explanationA mole is a unit of many particles (atoms, molecules, ions) where 1 mole is the number of particles contained in a substance that is the same amount as many atoms in 12 gr C-12
1 mole = 6.02.10²³ particles
[tex]\tt n=\dfrac{N}{N_o}[/tex]
N = number of particles
No = Avogadro number (6.02.10²³)
n = number of moles
While the number of moles can also be obtained by dividing the mass (in grams) with the molar mass of element or molecule
0.75 gram sample of Calcium Nitrate; Ca(NO₃)₂
MW of Ca(NO₃)₂ : 164.09 g/mol
[tex]\tt mol~Ca(NO_3)_2=\dfrac{0.75}{164.09}=0.00457[/tex]
The number of particles
[tex]\tt N=n\times N_o\\\\N=0.00457\times 6.02\times 10^{23}=2.75\times 10^{21}[/tex]
Which of the following forces weathers objects by expanding and changing shape?
Moving water
Wind
Plants
Ice
what kind of bond is between a halogen and an alkali metal
A given sample of oxygen occupies 500 mL when the pressure is 800 mmHg. What volume will the gas occupy at 200 mmHg, provided the temperature remains constant?
Answer:
The volume of the gas at 200 mmHg will be 2 L.
Explanation:
As the volume increases, the gas particles (atoms or molecules) take longer to reach the walls of the container and therefore collide with them fewer times per unit of time. This means that the pressure will be lower because it represents the frequency of collisions of the gas against the walls. In this way pressure and volume are related, determining Boyle's law which says:
"The volume occupied by a certain gaseous mass at constant temperature is inversely proportional to pressure"
Boyle's law is expressed mathematically as:
P * V = k
Now it is possible to assume that you have a certain volume of gas V1 that is at a pressure P1 at the beginning of the experiment. If you vary the volume of gas to a new value V2, then the pressure will change to P2, and it will be fulfilled:
P1 * V1 = P2 * V2
In this case:
P1= 800 mmHgV1= 500 mLP2= 200 mmHgV2= ?Replacing:
800 mmHg* 500 mL= 200 mmHg* V2
Solving:
[tex]V2=\frac{800 mmHg* 500 mL}{200 mmHg}[/tex]
V2= 2,000 mL= 2 L (being 1,000 mL=1 L)
The volume of the gas at 200 mmHg will be 2 L.
Assume that an object has been placed in the pan of a triple beam balance. The
scales of the balance are shown below. What is the mass of the object?
Answer:
190.4 g
Explanation:
To obtain the mass of the object, we must be able to obtain the reading of the triple beam balance.
Thus, the reading of the balance can be obtained by simply adding the various values as indicated by the pointer in each scale.
This can be obtained as follow:
Scale 1 = 90 g
Scale 2 = 100 g
Scale 3 = 0.4 g
Reading of the balance = Scale 1 + Scale 2 + Scale 3
Reading of the balance = 90 + 100 + 0.4
Reading of the balance = 190.4 g
Thus, the mass of the object as indicated by the triple beam balance is 190.4 g.
which factor affects an objects weight but not its mass?
A. Volume
B.Magnetism
C. Gravity
D Conductivity
Answer:
Gravity
Explanation:
Gravity is the pull of an object to another object like a human to the Earth. This is weight.
Answer:
C. Gravity
Explanation:
Just Took The Test And Got A Perfect Score. ;)
PLEASEEE HELPPP!!!! AND EXPLAIN PLS
Answer: True?
Explanation: THere is no question but I do know that is true because I answers that on a test and got it right. It was asking about:
how many Helium and oxygen molecules = H2O = + O2
Metals typically lose electrons and become cations lose electrons and become cations lose electrons and become anions lose electrons and become anions gain electrons and become anions gain electrons and become anions gain electrons and become cations
Answer:
Metals typically loose electrons and become cations
Explanation:
Metals are typically found towards the left hand side of the periodic table. They typically possess fewer electrons in their outermost shell compared to nonmetals.
As a result of this, when metals form chemical bonds with other elements, it is energetically more favourable for metals to loose electrons and form cations.
A combustion reaction occurs between one molecule of methane (CHa) and two molecules of oxygen (O2).
How many atoms of carbon, hydrogen, and oxygen make up the products for this combustion reaction?
O A) 1 carbon, 1 hydrogen, and 1 oxygen
O B) 1 carbon, 1 hydrogen, and 2 oxygen
O C) 1 carbon, 4 hydrogen, and 2 oxygen
OD) 1 carbon, 4 hydrogen, and 4 oxygen
The total number of atoms make up the products :
D) 1 carbon, 4 hydrogen, and 4 oxygen
Further explanationComplete combustion of Hydrocarbons with Oxygen will produce CO₂ and H₂O compounds.
If O₂ is insufficient there will be incomplete combustion produced by CO and H and O
Hydrocarbon combustion reactions (especially alkanes)
For combustion of methane (CH₄) and two molecules of oxygen (O₂).
[tex]\tt CH_4+2O_2\rightarrow CO_2+2H_2O[/tex]
The number of atoms make up the products
CO₂ : 1 carbon, 2 oxygen
2H₂O : 4 hydrogen , 2 oxygen
The total number of atoms make up the products :
D) 1 carbon, 4 hydrogen, and 4 oxygen
Combustion Reaction:Combustion is a chemical process in which a substance reacts rapidly with oxygen and gives off heat.
Combustion of Hydrocarbons with Oxygen will produce CO₂ and H₂O compounds.
If O₂ is insufficient there will be incomplete combustion produced by CO and H and OFor combustion of methane (CH₄) and two molecules of oxygen (O₂).The number of atoms make up the products:CO₂ : 1 carbon, 2 oxygen
2H₂O : 4 hydrogen , 2 oxygen
Thus, the correct option is D.
Learn more:
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7. If we have the same number of protons and electrons, our atom is ___________________________.
A: Negative
B:Positive
Answer:
It's actually Neutral
Explanation:
equal number of negative electric charges (the electrons) and positive electric charges (the protons).
will ya'll help me, please
Answer:
Either A or D
But i think D
hope this helps =3
sorry if im wrong
One tank of gold fish is fed the normal amount of food once a day. A second tank is fed twice a day. A third tank is fed four times a day during a six week study. The fish's weight is recorded daily. All tanks were of the same size and shape. IV: DV: Control Group:
The question is incomplete, the complete question is;
One tank of goldfish is feed the normal amount which is once a day, a second tank is fed twice a day, and a third tank is fed four times a day during a 6 week study. The fishes' body fat is recorded daily.
Independent Variable-
Dependent Variable-
Constants
Control Group-
Answer:
A) The amount of food the gold fish receives
B) Body fat of the gold fish
C) -Type of fish used in the study (gold fish)
Time period within which the fishes were fed (Six week period)
Shape and size of tank
D) group of gold fish fed the normal amount
Explanation:
The purpose of the study is to determined the impact of amount of feed on the body fat of gold fish. Hence, the amount of feed is the independent variable while the body fat of the feed is the dependent variable.
The control group receives the normal amount of feed (once a day). The fishes are all gold fish, fed within a six week period. All the tanks were of the same shape and size. These are the constants in the study.
Help please 2 mins til it submits
Elements in the same _____ on the periodic table have the same number of valence electrons.
How can some of the difficulties caused by the Down Syndrome be over come?
The sphere was dropped into water in a graduated cylinder as shown below
Answer:65 ML
Explanation:
How are hypotheses different from theories?
Answer:
Explanation:
This is the Difference Between a Hypothesis and a Theory. In scientific reasoning, a hypothesis is an assumption made before any research has been completed for the sake of testing. A theory on the other hand is a principle set to explain phenomena already supported by data.
Does the number of molecules change when a substance changes state?
Answer:
Molecules do't break up and reform when a substance boils and cools. Particles stay the same size and shape during state changes.
Explanation:
brainliest will be appreciated
two atoms are isotopes of the same element, the atoms must have
Answer:
the answer is isotopes
I hope this will help you
True or False?
To increase acceleration of a object, you reduce its mass or increase the applied force.
help please lol I’m stuggling
Answer:
balenced
Explanation:
Which postulate of Dalton’s atomic theory has not been disproved by further investigation?
A. All matter is made of tiny particles called atoms.
B. Atoms are indivisible and indestructible.
C. All atoms of a given element have the same mass.
D. Atoms of an element are all identical.
Answer:
The indivisibility of an atom was proved wrong: an atom can be further subdivided into protons, neutrons and electrons...
hope this helps u
The Daltons atomic model gave the theory of chemical combination and the law of conservation of atoms. All matter is made of atoms is not disapproved. Thus, option A is correct.
What was Dalton’s atomic theory?Dalton’s atomic theory was given by John Dalton and involved several main points. According to the theory that matter has been composed of tiny atoms that are indestructible and indivisible.
It also stated about the mass, as atoms of various elements have different masses and the properties are shared by the atoms of the same element only. It gave rise to the law of conservation of mass, definite, and multiple proportions.
One of the laws is about matter being made of tiny particles called atoms. It has been not disproved by further investigation in any of the atomic models and theories.
Therefore, option A. the matter is made of atoms is not disproved.
Learn more about Dalton’s atomic theory, here:
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What Element am I?
I have 5 Valence Electrons.
I am in the 5th row.
My atomic mass is less than Bismuth *
с
Answer:
Nitrogen
Explanation:
Nitrogen has 5 Valence Electrons.
And its atomic mass is also less than Bismuth.
There are other elements in the 5th row but this one has the lowest atomic mass compared to the others.
Pleaseee help me on this
PLEASE HELP I NEED HELP ASAP I WILL GIVE BRAINLIEST AS SOON AS POSSIBLE
Answer:
1 . 2.393e+ 9
2. ???
3. 3.25e-6
Explanation:
2393 kg = 2.393e+9 mg
43.23 g = 4.323 dam
0.325 cm = 3.25e-6 km
(Note: I'm not 100% that these are correct, but I hope this helps you tho. ^^)
PLEASE ANSWER FAST
A model of an atom is shown above. The blue dots represent electrons, and the red dot represents the nucleus. This model accurately represents
A.
that electrons are found everywhere in an atom, even in the nucleus.
B.
what an atom would look like when seen through a microscope.
C.
that a single atom may have many nuclei.
D.
that the nucleus is located at the center of the atom.
Answer:
D. that the nucleus is located at the center of the atom
I hope that this helps!
There are several atomic models which explain the structure of atoms. Here the given model of atom is similar to Rutherford's model of atom. The nucleus is located at the center of the atom. The correct option is D.
What is Rutherford's atomic model?In Rutherford's atomic model, he bombarded a thin sheet of gold foil with high energy alpha particles and made several observations. He said that most of the space inside the atom is empty. A heavy positively charged body called nucleus is present inside the atom.
The nucleus is capable of repelling and deflecting highly energetic alpha particles and also has a appreciable mass and charge. The volume occupied by the heavy positively charged body must be very very small.
Here in the given model, blue dots are electrons which revolve around the nucleus and the red dot is the nucleus which is present at the centre.
Thus the correct option is D.
To know more about Rutherford's model, visit;
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I need help with 2, 3, and 4 please help i will give the brainliest
Answer:
2=2.28*10^5
3=3.98*10^3
4=5.76*10^3
The equation 1/2 N2 + 3/2 H2+ NH3 is not appropriately written because
Answer:
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Which element has a greater atomic radius Mg or Cl?
the only nonmetal in group 1
Answer:
Hydrogen
Explanation:
Hydrogen is the only non metal in group on of the period table of elements.
HELP ASAP!! FILL IN THE BLANKS! will be brainliest!!!
Answer:
Don't mark me brainliest because of this but I'm pretty sure your supposed to give us the words because teachers don't give you things like that without the words you will the answer in with.
Answer:
Same as number of NUETRONS
POSITIVE charge
number of protons is the same as the atomic NUMBER
Located in the Nucleus
Larger mass than ELECTRONS
Explanation:
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