Fluorine, I still remember this from my science fair
what is a chemical change? and what is a physical change?
In a chemical reaction, there is a change in the composition of the substances in question; in a physical change there is a difference in the appearance, smell, or simple display of a sample of matter without a change in composition.
A chemical change is a change where something new can be formed and normally can not be changed back. Examples of a chemical change are precipitates being formed, gases being formed, quick temperature change rust, bubbling, foaming, burning, etc. A physical change is a change where nothing new is formed and normally can be changed back. For example you painted a wooden block red. If you want, you can always change the color again. Nothing chemically or permanantly happened to it. More examples of a physical change are; color change, change of state, luster, shape, size, hardeness, etc.
:)
is methane used as fule
gas true or false
Answer:
its true methane is used as a fuel gas
Explanation:
X-rays had a frequency of about 3x10^18 determine it's wavelength (in nm) and energy per photon
Answer:
λ = 0.1 nm
E = 2 × 10⁻¹⁵ J
Explanation:
Step 1: Given data
Frequency of X-rays (ν): 3 × 10¹⁸ s⁻¹
Step 2: Calculate the wavelength (λ) of a photon of X-rays
We will use the following expression.
c = λ × ν
where,
c: speed of light
λ = c / ν
λ = (3.00 × 10⁸ m/s) / 3 × 10¹⁸ s⁻¹
λ = 1 × 10⁻¹⁰ m × (10⁹ nm/1 m) = 0.1 nm
Step 3: Calculate the energy (E) of a photon of X-rays
We will use the following expression.
E = h × ν
where,
h: Planck's constant
E = 6.63 × 10⁻³⁴ J.s × 3 × 10¹⁸ s⁻¹
E = 2 × 10⁻¹⁵ J
What is the approximate energy of a photon having a frequency of 4 x 10^7 Hz? (h = 6.6 x 10^-34 J . s)
Answer:
2.64 ×[tex]10^{-26}[/tex] J
Explanation:
I think you should mark it a physics question instead but anyway.
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The Planck equation should be applied:
E = hv , while E is energy of proton; h is Planck constant; and v is frequency.
E = 6.6 × [tex]10^{-34}[/tex] × 4 × [tex]10^{7}[/tex]
= 6.6 × 4 × [tex]10^{-27}[/tex]
= 2.64 ×[tex]10^{-26}[/tex] J
A species of kangaroo has a diploid chromosome number of 16. After meiosis, to develop the kangaroo’s sperm or egg, the haploid number would be
. When fertilization occurs, the zygote would again have 16 chromosomes.
Answer:
Just to prove that the persons answer on top of mine is correct :D
Explanation:
Answer:
Explanation:
8
50 POINTS..!!! NEED RHE ANSWER ASAP..!!! consider the original wave at the top of the illustration. compare the original wave to the other four. which wave represents a wave with the same volume but a lower pitch?
a). wave a
b). wave b
c). wave c
d). wave d
Answer:
my best guess is b
Explanation:
typically the lower the pitch the longer the wave line inbetween the inclines are
what would you need to do to calculate the molarity of 10g of NaCl in 2kg of water?
A. convert the 10 g of NaCl to Kg of NaCl
B. Convert the 10g of NaCl to moles of NaCl
C. Convert the 2kg of water to liters of water
D. Convert the 2kg of water to moles of water
Answer:
B) we will convert the 10 g of NaCl into moles.
Explanation:
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
we will convert the 10 g of NaCl into moles.
Number of moles of NaCl:
Number of moles = mass/molar mass
Number of moles = 10 g/ 58.44 gmol
Number of moles = 0.17 mol
1 Kg = 1 L
Molarity = 0.17 mol / 2 L
Molarity = 0.085 mol/L
Molarity = 0.085 M
Answer:
B. Convert the 10g of NaCl to moles of NaCl
What is the bond angle that corresponds to the
geometry associated with C1 in the structure?
A. 120° B. 90O
C. 1800
D. 109.5o
7. Between which bonded elements in the above
structure is there the strongest dipole moment?
A. Carbon to Carbon B. Hydrogen to Carbon
C. Oxygen to Carbon D. Oxygen to Hydrogen
8. What is the geometry associated with the C2 molecule in the structure?
A. linear B. trigonal planar C.bent D. tetrahedral
9. Among the choices below, which correctly describes the bonding taking place in the above structure?
A. 6 sigma bonds, 1 pi bond C. 6 sigma bonds, 2 pi bonds
B. 7 sigma bonds, 1 pi bond D. 7 sigma bonds, 2 pi bonds
If 56 grams of nitrogen is mixed with 56 grams of oxygen, what is the pressure of each gas if the total
pressure is 1320 Torrs?
Answer:
pN₂ = 695 torr; pO₂ = 625 torr
Explanation:
Step 1: Calculate the moles of each gas
The molar mass of N₂ is 28.01 g/mol.
56 g × 1 mol/28.01 g = 2.0 mol
The molar mass of O₂ is 32.00 g/mol.
56 g × 1 mol/32.00 g = 1.8 mol
Step 2: Calculate the total number of moles
n = nO₂ + nN₂ = 1.8 mol + 2.0 mol = 3.8 mol
Step 3: Calculate the partial pressure of each gas
We will use the following expressions.
pN₂ = P × X(N₂)
pN₂ = 1320 torr × (2.0 mol/3.8 mol)
pN₂ = 695 torr
pO₂ = P × X(O₂)
pO₂ = 1320 torr × (1.8 mol/3.8 mol)
pO₂ = 625 torr
M. element
cenabrecht
0.5 mele of an
Answer:
Number of moles (n)=
molecular weight
weight
Weight=n×Molecular weight
=0.5×14
Mass=7g
What did the Curies conclude about radioactivity based on their studies?
A. The amount of radioactivity is an extensive property because it varies as the amount of material varies.
B. The amount of radioactivity is an extensive property because it remains constant as the amount of material varies.
C. The amount of radioactivity is an intensive property because it varies as the amount of material varies.
D. The amount of radioactivity is an intensive property because it remains constant as the amount of material varies.
Answer:
c
Explanation:
In order to determine if 2 atoms are cooper what must be the same for each
How does the atomic radius of an element is related to its metallic character
Answer:
The large the atomic radius the more the metallic character of elements
Explanation:
The atomic radius is related to the metallic character in a way that the larger the atomic radius, the more metallic a body becomes.
Therefore, as we go down a group, metallic character increases.
Metallic character relies on the ability and willingness of an atom to share its valence electrons. As the size of an atom becomes large, the more metallic it is and the more its metallic character. In some other cases this character is known as electropositivity.What is responsible for the blue sky?
Answer:
sun shine
Explanation:
Sunlight reaches Earth's atmosphere and is scattered in all directions by all the gases and particles in the air. Blue light is scattered more than the other colors because it travels as shorter, smaller waves. This is why we see a blue sky most of the time
Answer:
Sunlight
Explanation:
Sunlight reaches Earth's atmosphere and is scattered in all directions by all the gases and particles in the air. Blue light is scattered more than the other colors because it travels as shorter, smaller waves. This is why we see a blue sky most of the time. Blue light is scattered in all directions by the tiny molecules of air in Earth's atmosphere. Blue is scattered more than other colors because it travels as shorter, smaller waves. This is why we see a blue sky most of the time. ... Also, the surface of Earth has reflected and scattered the light.
Both the esophagus and the small intestine are involved in the digestion of food. The esophagus squeezes food into the stomach by wave-like muscle contractions. Peptidase enzymes in the small intestine break food molecules into smaller molecules.
Which statement best describes changes to food during digestion?
A. The muscle contractions result in physical changes, while the action of the peptidase results in chemical changes.
B. The muscle contractions result in chemical changes, while the peptidase results in physical changes.
C. The muscle contractions and the action of the peptidase both result only in physical changes.
D. The muscle contractions and the action in the peptidase both result only in chemical changes.
Answer:
The answer is: A
Explanation:
The wave-like contractions are to be considered a physical change as they do not take part in the breaking-down of the food. The peptidase is a chemical change because it is used to chemically break down the food to retrieve nutrients and such.
Which statement best describes what would happen to an ecosystem once the sun is removed?
A. The functions within the ecosystem will eventually stop & everything will die off.
B. The ecosystem will continue to thrive; it does not need the sun's energy to work.
C. The ecosystem will look for a different source of energy to use.
D. The ecosystem will instantly stop working.
Answer:
A. The functions within the ecosystem will eventually stop & everything will die off.
Explanation:
Everything is dependent on the sun --starting from the bottom of the food chain, the producers. However, we wouldn't die instantly because "Earth retains heat fairly well, so humans wouldn't freeze instantly."
Match each item with the correct statement below.
a.
Intramolecular force
d.
Intermolecular forces
b.
tetrahedral
e.
London dispersion Forces (LDFs)
c.
linear
____ 1. An intermolecular force that occurs between two molecules of Br2 is formed by?____
____ 2. Is a force that occurs within molecules and compounds.
____ 3. Dipole – dipole, Hydrogen Bond, and London dispersion Forces are examples of what type of force?
____ 4. Is the molecular shape of HI.
__ 5. the molecular shape of CH4
1. LDFs
2. Intermolecular Forces
3. Intramolecular Forces
4. Linear
5. Tetrahedral
Edit: I'm new to this site and idk how to use it properly. I'm not sure about 2 and 3 currently because these forces are between molecules as well so INTERmolecular would be used twice (?)
Write True/False against the following statements and also correct the false statement.
Greater the calorific value better is the fuel.
Answer:
I think it is true you should go for true
please help im stuckkkk
Answer:
Just in case you want confirmation yes, its mid ocean ridge
Which phrase justifies why the theory of evolution is a theory and not a law?
1. Describes the relationship between an organism and its environment
2. Makes accurate predictions based on only a small amount of empirical evidence
3. Explains diversity based on the principle of natural selection
4. Cannot be modified with the discovery of new evidence
Answer:
2. Makes accurate predictions based on only a small amount of empirical evidence
Explanation:
For a phrase or scientific finding to be considered a law, there has to be clear evidence and facts to support that specific finding. In the case of the evolution theory, the evidence is not clear enough to make it a law
Answer:
2. Makes accurate predictions based on only a small amount of empirical evidence
Explanation:
HELP
1) A 400g sample of alcohol (c = 2.43 J/g°C) at 16°C is mixed with 400g
of water (c = 4.19 J/g°C) at 85°C. What is the final temperature of the
mixture?
Answer:
Explanation:
Given data:
Mass of alcohol = 400 g
Specific heat capacity of alcohol = 2.43 J/g°C
Initial temperature of alcohol = 16°C
Mass of water = 400 g
Specific heat capacity of water = 4.19 J/g°C
Initial temperature of water = 85°C
Final temperature of mixture = ?
Solution:
Equation:
m₁c₁ (T₂-T₁ ) = m₂c₂(T₂-T₁)
by putting values,
400 × 4.19 × (T₂ - 85°C) = 400 × 2.43 × (T₂ - 16°C)
1676 × (T₂ - 85°C) = 972 × (T₂ - 16°C)
How is Zinc chloride formed in the lab and please tell the steps
Answer:
When zinc metal is reacted with hydrochloric acid, hydrogen gas is released and an aqueous solution of zinc chloride is produced. ... It is important that all of the zinc used be reacted and that large excess amounts of hydrochloric acid not be used.
Anhydrous zinc chloride is synthesized by treating zinc with hydrogen chloride. Whereas, hydrated and aqueous forms of zinc chloride are prepared by treating zinc with hydrochloric acid. Zinc metal could either be in the form of zinc sulfide or zinc oxide
Have a nice Day , Hope this helped you I would appreciate it if you could mark my answer brainliest
Merry Christmas
Answer: Anhydrous zinc chloride is synthesized by treating zinc with hydrogen chloride. ... Zinc metal could either be in the form of zinc sulfide or zinc oxide. ZnS(s) + 2 HCl(aq) → ZnCl2(aq) + H2S(g) There are impurities present in zinc chloride samples due to hydrolysis.
got this from goo.gle
Hope this helps.......... Stay safe and have a Merry Christmas!!!!! :D
D
Magnesium carbonate decomposes on heating to form magnesium oxide and carbon dioxide as
shown.
MgCO3 → MgO + CO2
How much magnesium carbonate is needed to make 5.0g of magnesium oxide?
А
3.5g
B 4.09
C 6.5g
D 10.59
The amount of 10.5 g magnesium carbonate is needed to make 5.0g of magnesium oxide.
So, option D is correct.
Given that, Magnesium carbonate decomposes on heating to form magnesium oxide and carbon dioxide as
MgCO₃ → MgO + CO₂
Molar mass of MgCO₃ = 24 + 12 + 48 = 84 g/mole
Molar mass of MgO = 24 + 16 = 40g/mole
40 gram MgO is produced from 84 gram of MgCO₃
1 gram of MgO produced from [tex]\frac{84}{40}=2.1[/tex] gram of MgCO₃
Therefore, 5 gram of MgO produced from [tex](5*2.1=10.5gram)[/tex] of MgCO₃
Thus, option D is correct.
Learn more about molar mass here:
https://brainly.com/question/22503632
1. Does elevation play a factor? If so, can the elevation be changed to protect the homes? 2. Could the residents build a structure that would prevent a tsunami from reaching the community? What would this structure look like? How would the residents build it? 3. What could limit the erosion of the beach?
Answer:
Yes.
Explanation:
Yes, elevation play a great role and has the ability to protect homes from natural disasters such as flood and tsunami etc. The residents build a hard structure of wall along the beach that would prevent a tsunami from reaching the community and also built homes at higher elevation. The residence built it with the help of government and this wall is also effective in reducing the erosion of the beach.
Answer:
1. Yes elevation does play a factor if the house was higher i feel like it wouldnt get as damaged
2. Yes they could build a high enough wall that it would take most of the impact away from the houses, you would build it with the thickest peice of wood that you could find and use long screws and cement the wood into the ground.
3. The wall will also help from erosion
Explanation: i got it right on my project.
A silver ring reacts with compounds containing sulfur in the air to form silver sulfide, a black substance that makes up the tarnish on the surface of silver objects. To remove the tarnish from the ring, students placed it in a pan lined with aluminum foil and added hot water. Baking soda was added to the hot water and stirred. Students made observations about the process. Which observation of this process provides evidence of a chemical reaction?
Question 4 options:
A Hot water heated the aluminum foil.
B The liquid solution changed color.
C The pan was lined with aluminum foil.
D The hot water cooled.
Answer:
c lined with aluminum foil
What object do you think will take up
more space? Why do you think this?
Answer:
solids
Explanation:
BC they r heavier than liquid and gas
What is Newton's First Law known as? The Law of
____
Answer:
inertia
Explanation:
Answer:
Law of inertia, also called Newton's first law, postulate in physics that, if a body is at rest or moving at a constant speed in a straight line, it will remain at rest or keep moving in a straight line at constant speed unless it is acted upon by a force.
Explanation:
hope it helps, please mark brainliest
Question 10 of 32
Which of the following is an example of how the same chemicals used to
help people can harm the environment?
O A. Phosphates are removed from detergents so they don't end up in
drinking water.
B. Hillsides erode after plants are removed to clear a space for crops.
C. Plants grow back after toxic chemicals are removed from the
surrounding soil.
D. Excess fertilizers run off into rivers and create a dead zone.
SUBMIT
Answer:
D
Explanation:
The correct answer that gives a good example of how the same chemical used to help people can harm the environment would be when excess fertilizers run off into rivers and create a dead zone.
Fertilizers are usually applied to crops as an agricultural practice by farmers to enhance the yield of the crops and boost food or raw materials production. However, excess fertilizer gets washed into nearby water bodies and ends up creating a low-oxygen zone that is incapable of supporting lives within the water body - also known as dead zones.
The correct option is, therefore, D.
Why does salt sprinkled on icy roads cause the ice to melt?
Answer:
The actual reason that the application of salt causes ice to melt is that a solution of water and dissolved salt has a lower freezing point than pure water. When added to ice, salt first dissolves in the film of liquid water that is always present on the surface, thereby lowering its freezing point below the ices temperature. Ice in contact with salty water therefore melts, creating more liquid water, which dissolves more salt, thereby causing more ice to melt, and so on.
Diffraction is a wave property that electrons possess
- true
- false
Answer:
The given statement is "True". A further explanation is provided below.
Explanation:
Diffraction occurs mostly with general noise, with electro-magnetic radioactive material, such as visible region, x-ray, but mostly gamma rays, and with very small moving molecules, such as atomic nuclei, as well as electrons, that also have wavelike characteristics. Yet another side effect of diffraction is because there are no dramatic or rapid shadows.Therefore this obvious response is the right one.