Answer:
Physical
Explanation:
When something melts it is still the same substance.
For example:
Ice and water are still both water, so that would be a physical change.
If a reaction changes the substance into a new/different substance then it is a chemical change.
21.7 mol Rn =
Rn atoms
You have convert please help❤️
Answer:
130.68 × 10²³ atoms
Explanation:
Given data:
Number of moles of Rn = 21.7 mol
Number of atoms = ?
Solution:
Avogadro number:
It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance. 6.022 × 10²³ is called Avogadro number.
1 mole = 6.022 × 10²³ atoms
21.7 mol × 6.022 × 10²³ atoms / 1mol
130.68 × 10²³ atoms
Ight I just here’s my first one
Answer:
D
Explanation:
What is a simulation? Why are simulations helpful to scientists?
Answer:
A simulation is an imitation. Simulations are helpful to scientists because they allow scientists to study occurrences more closely.
Explanation:
Explanation:
A simulation is a way of imitating a process or change in the real world to predict what will happen or explain what did happen and why, these days simulations are often run on computer,scientists use simulations to answer questions see how complex system works test ideas and make predictions, hope it helps^^
btw I'm no expert, I did research^^
Please help me I need an answer ASAP
are the answers correct ?
Answer:
yeh they are all correct .
Does recycling plastic solve the issue of using crude oil?
Answer:
Every single tonne of recycled plastic cuts carbon emissions by 1.6t and preserves 2t of crude oil. And each tonne that is recycled is not just one tonne less which the industry has to buy as crude oil on the global market – it is also one tonne less of waste plastic in our seas and oceans.
4. What happens when a bond is formed between a greenish yellow gaseous element X and a
soft metallic element Y.
A Atom X gains an electron.
B Atom X loses an electron.
С Atom Y gains an electron.
D X and Y share a pair of electrons
Answer:
A. Atom x gains an electron
Explanation:
What happens when a bond is formed between a green gaseous element and a soft metallic element?（2.0分）
A. The gas atoms gain an electron.
B. The gas atoms lose an electron.
C. The metal atoms gain an electron.
D. The two elements share a pair of electrons
Atom X gains an electron because it needs electron to become stable.
Atom Y loses electron and atom X gains an electron in order to complete its outermost shell. Atom Y belongs to metal which has one electron while on the other hand, atom Y belongs to halogens which needs one electron for the completion of its outermost shell and become stable so atom Y loses one electron and atom X gains that electron and attain the electronic configuration of noble gases so we can say that Atom X gains an electron.
Learn more: https://brainly.com/question/19509418
Which has a higher melting point KF or NaF
Air is a natural resource .
Ture
False
Sound _____.
travels in transverse waves
requires a medium to travel through
travels most slowly through solids
speeds up when temperature is increased
is changed into electrical impulses by the cochlea
Answer:
Sounds travels in transverse waves requires a medium to travel through
Answer:
The answer is A
Explanation:
just got it correct on a quiz
At which location are metamorphic rocks most likely to
form?
оооо
D
С
В
A
Done
Intro
HELP PLEASE
Answer:
D
Explanation:
Answer:
c
Explanation:
What kind of energy makes your hair frizzy
Answer:
electricity
Explanation:
static hair occurs when your hair builds up an electric charge
true of false. A d-orbital lies in the x, y, and z area defined by the geometric axis of space.
Answer:
true
Explanation:
Please answer quick. In an experiment, a student collects 107 mL of H2 over water at a pressure of 104.8 kPa and a temperature of 30°C. How many grams of H2 are present?
A.
0.024 g
B.
4.00 g
C.
0.04 g
D.
0 049 g
And explain
Answer:
Mass = 0.008 g
Explanation:
Given data:
Volume of H₂ = 107 mL
Pressure = 104.8 KPa
Temperature = 30°C
Mass of H₂ present = ?
Solution:
Formula:
The given problem will be solve by using general gas equation,
PV = nRT
P= Pressure
V = volume
n = number of moles
R = general gas constant = 0.0821 atm.L/ mol.K
T = temperature in kelvin
Now we will convert the units of temperature, pressure and volume.
Temperature = 30+273 = 303 K
Volume of H₂ = 107 mL (107/1000= 0.107 L)
Pressure = 104.8 KPa (104.8/101 = 1.04 atm)
by putting values,
1.04 atm ×0.107 L = n× 0.0821 atm.L/ mol.K × 303 K
0.11 atm.L = n×24.87 atm.L/ mol
n = 0.11 atm.L / 24.87 atm.L/ mol
n = 0.004
Mass of H₂:
Mass = number of moles × molar mass
Mass = 0.004 mol × 2 g/mol
Mass = 0.008 g
Some elements can make ions when what event occurs? Question 8 options: The gain of an electron The loss of a neutron The gain of a neutron The gain of a proton
Answer:
The gain of an electron.
Explanation:
Ions are made when an atom does no longer have an equal number of protons and electrons.
This would theoretically mean that in order for an atom to become an ion, it would have to either gain or lose an electron or a proton.
However, protons are located in the nucleus, so the energy required to add or remove a proton is immensely higher than the energy required to add or remove an electron.formula for salt
I will mark u brain list
Answer:
The formula for salt is NaCl or Sodium chloride
Chlorine has a total of 17 electrons and 7 Valence electrons. Why are these two numbers
different?
Chlorine contains a total of 17 electrons which are filled in different orbitals of which 7 electrons are located in the outermost energy level or orbital.
What are valence electron?In an atom, the electrons are surrounding the nucleus through fixed paths or energy levels called orbitals. Electrons are filled in the increasing order of energy level. Thus lower energy levels are filled first.
The last electrons are filled in the outermost energy levels and are called valence electrons. Each shell have a definite capacity for electrons.
Cl is 17the element in periodic table and has 17 electrons of which 7 electrons are located in the outermost shell. Hence, option A is correct.
To learn more about chlorine, find the link below:
https://brainly.com/question/14962130
#SPJ5
What type of solid is formed when a bond occurs between magnesium and oxygen?
1) Metallic
2) Molecular
3) Ionic
4) Network
Answer:
3) Ionic
Explanation:
The solid formed when a bond occurs between magnesium and oxygen is an ionic bond. This bond type occurs between a metal and non-metal.
Magnesium is the metalOxygen is the non - metalDue to the large electronegativity difference between the two species, the metal loses electrons which the non-metal oxygen gains They both complete their octet and electrostatic attraction leads to the formation of ionic bonds.On a hot day, you sit on the edge of a pool and dip your feet into the water, causing changes to occur that are related to the physical and thermal properties of your feet and of the water. Select the statements that accurately describe what is happening, in terms of the heat and temperature of the objects and substances. There may be more than one accurate statement.
A.
Cold from the water reduces the temperature of your feet.
B.
Heat from your feet raises the temperature of the water.
C.
Your feet transfer heat into the surrounding water, reducing the temperature of your feet.
D.
Cold from the water moves into your warm feet.
What mass of citric acid (molar mass = 192.14g/mol) would be needed to make 0.10 L of 5.00 M citric acid solution ?
Answer:
Mass = 96.07 g
Explanation:
Given data:
Mass of citric acid = ?
Molar mass of citric acid = 192.14 g/mol
Volume of citric acid solution = 0.10 L
Molarity of solution = 5.00 M
Solution:
First of all we will calculate the number of moles from molarity formula. Then we will determine the mass from moles formula.
Molarity is used to describe the concentration of solution. It tells how many moles are dissolve in per litter of solution.
Formula:
Molarity = number of moles of solute / L of solution
5.00 M = n/0.10 L
n = 5.00 mol/L× 0.10 L
n =0.5 mol
Mass of citric acid:
Number of moles = mass/molar mass
0.5 mol = mass/ 192.14 g/mol
Mass = 0.5 mol × 192.14 g/mol
Mass = 96.07 g
When 38.1 grams of a certain metal at a temperature of 90.0°C is added to 100.0mL of water at a temperature of 17.6°C in a perfectly insulated calorimeter, the final temperature of the resulting mixture is 19.1°C. a. Find the value of q for the metal b. Find the value of q for the water c. What is the specific heat of the metal?
Answer:
a. qm = 627.3 J
b. qw = 627.3 J
c. C₂ = 227.4 J/kg.°C
Explanation:
a.
Since, the calorimeter is completely insulated. Therefore,
Heat Lost by Metal = Heat Gained by water
qm = qw
qm = m₁C₁ΔT₁
where,
qm = heat lost by metal = ?
m₁ = mass of water = (density)(volume) = (1000 kg/m³)(100 mL)(10⁻⁶ m³/1 mL)
m₁ = 0.1 kg
C₁ = specific heat capacity of water = 4182 J/kg.°C
ΔT₁ = Change in Temperature of Water = 19.1°C - 17.6°C = 1.5°C
Therefore,
qm = (0.1 kg)(4182 J/kg.°C)(1.5°C)
qm = 627.3 J
b.
Since,
qm = qw
qw = 627.3 J
c.
qm = m₂C₂ΔT₂
where,
m₂ = mass of metal = 38.1 g = 0.0381 kg
C₂ = specific heat capacity of metal = ?
ΔT₂ = Change in Temperature of metal = 90°C - 17.6°C = 72.4°C
Therefore,
627.3 J = (0.0381 kg)(C₂)(72.4°C)
(627.3 J)/(0.0381 kg)(72.4°C) = C₂
C₂ = 227.4 J/kg.°C
When Jeremy returned home after vacation, he noticed that his new plant had not grown. His mother, a florist, told him that it was because the plant was not getting enough sunlight. He moved his plant closer to the window to get more sunlight. How can Jeremy best support the idea that his plant needs more sunlight? Ask his mother to make the plant better. Wait and see what happens to the plant. Remove the plant from direct sunlight after a week. Ask his science teacher at school what she thinks could be the reason.
Answer:
Wait and see what happens to the plant.
Explanation:
The best course of action for Jeremy would be to wait and see what happens to the plant after moving it closer to the window to get more sunglight.
If the plant grows after observing it for some times, he can conclude that light has been a major hindrance to the growth and more sunlight would benefit the plant. If the observation is otherwise, then Jeremy can conclude that the lack of growth observed is not due to light.
Answer:
remove the plant from direct sunlight after a week
Explanation:
Molecules of a gas _____.
move slowly and are far apart
move fast and are far apart
move slowly and are close together
move fast and are close together
Answer:
Explanation:
Move fast and are far apart is the correct answer
Pwease halp, If a decrease in temperature accompanies a reaction, what occurred?
Energy was released.
Energy was destroyed.
Energy was created.
Energy was absorbed.
Answer: energy was released.
Explanation: i took the quiz.
A mixture is a combination of
I give Brainly
I need the answer now plz
two or more pure substances in
which each pure substance retains
its individual chemical properties.
A mixture is physically, not
chemically, combined.
Example: salt and sugar
combined together in a bowl
I need 2 more examples
Answer:
Sand and water
Oil and sand
Explanation:
A mixture, has rightly stated in this question, is a substance composed of two or more substances combined physically rather than chemically. In a mixture, each constituent retains its chemical properties i.e. the chemical properties of none of the substances in a mixture is altered. This serves as the basis for the physical separation of a mixture.
One example of mixture has been given in this question i.e salt and sugar combined together in a bowl. This represent a mixture because the sugar is not chemically combined to the salt, hence, each can easily be separated. This is the same for any other mixtire. More examples include:
Sand and water
Oil and sand
Salt and water (salt solution)
Petroleum or crude oil
What is the most obvious sign of bias in a historical text?
A.
incorrect information and lack of reference sources
B.
strong language, expressing either like or dislike
C.
repetition of the same information over and over
D.
talking only about a single historical event
Answer:
the answer is b,the answer has to be even though I'm not very sure about it
which molecules are used to produce energy
Answer:
Explanation:
fats, proteins, and carbohydrates
what element is
Column 16, period 3
Answer:
The element is Sulfur.
Explanation:
Write an explanation on how filtration works, using the words: soluble and unsoluble.
Answer:
If a substance does not dissolve in a solvent, we say that it is insoluble. For example, sand does not dissolve in water – it is insoluble.
Filtration is a method for separating an insoluble solid from a liquid. When a mixture of sand and water is filtered:
the sand stays behind in the filter paper (it becomes the residue)
the water passes through the filter paper (it becomes the filtrate)
The slideshow shows how filtration works
Explanation:
1st
A beaker containing a mixture of insoluble solid and liquid. There is filter paper in a filter funnel above another beaker.
2nd
The mixture of insoluble solid and liquid is poured into the filter funnel.
3rd
The liquid particles are small enough to pass through the filter paper as a filtrate. The solid particles are too large to pass through the filter paper and stay behind as a residue.
Answer:
Filtration is the action or process of filtering something. Filtration is the method used for separating an insoluble solid from a liquid. Ex - oil and water
I am really sorry but I don't know how to include the word solube!!!
what type of mixture is table salt
Answer:
The chemical mixture of table salt is NaCl.