Pedro is baking a cake for his experiment on chemical changes. He knows a chemical change will occur when he puts the cake mixture in the oven. He would like to know what will happen when the cake is removed from the oven. What prediction would you make for Pedro's experiment? A. The chemical changes occurred because the chemicals changed. B. The chemical changes occurred because there was a change in light energy. C. The fruit and the hamburgers were affected by an increase in heat energy. D.The fruit and the hamburgers were affected by a decrease in heat energy.
Answer:
A. The chemical changes occurred because the chemicals changed.
Explanation:
When baking a cake several chemical reactions occur that change the chemical composition of the ingredients used in baking. An ingredient like baking powder releases carbon dioxide when it undergoes a temperature change in the oven. A chemical change is supposed to change the form of a substance.
An endothermic reaction also occurs when the ingredients absorb heat energy to produce several changes. The firmness of the cake occurs because of the heat absorbed by the proteinous content of the egg.
Chloe is training for her first half-marathon, which requires her to run 21.1 km. Before she runs, she carefully chooses the foods that will give her the energy her body requires for the race. She stands still at the starting line, then she starts running, her body warming up as she runs. Which three energy transformations take place in this example? Potential energy to kinetic energy Chemical energy to thermal energy Chemical energy to kinetic energy Mechanical energy to chemical energy
Answer:
The transformation is of chemical energy (use the ATP molecule as a resource) which is then transformed into mechanical energy (muscle contraction) and finally transformed into thermal energy (increase in body temperature, or sweating)
Explanation:
Energy is never lost, it is always transformed, that is why energy is yielding electronic movement and expressing itself in different ways, first as chemical energy, then as mechanical energy, and lastly as thermal energy.
It is important to clarify that the energy source of all this transformation is food and energy reserves.
NEED HELP ASAP WITH THESE QUESTIONS GIVING FAIR AMOUNT OF POINTS IF HELPED WITH ALL QUESTIONS Violet light has a wavelength of 4.20 x 10-12 m. What is the frequency?
3. A photon has a frequency (n) of 3.468 x 106 Hz. Calculate its energy
Calculate the energy (E) and wavelength (l) of a photon of light with a frequency of 4.215 x 1014 Hz.
Calculate the frequency and the energy of blue light that has a wavelength of 400 nm
(h = 6.62 x 10-34 J-s).
Calculate the wavelength and energy of light that has a frequency of 9.5 x 1015 Hz.
A photon of light has a wavelength of 0.090 cm. Calculate its energy.
Calculate the energy and frequency of red light having a wavelength of 2.80 x 10-5 cm.
Calculate the energy (E) and wavelength (l) of a photon of light with a frequency of 5.165 x 1014 Hz.
The wavelength of green light from a traffic signal is centered at 7.20 x 10-5 cm. Calculate the frequency.
If it takes 1.56 seconds for radio waves (which travel at the speed of light) to reach the moon from Earth, how far away is the moon?
Calculate the frequency of light that has a wavelength of 4.20 x 10-9m. Identify the type of electromagnetic radiation.
Answer:
a) 7.14e19 Hz
b) 2.298e-27 J
c) 2.793e-19 J; 7.117e9 nm
d) 7.5e14 Hz; 4.96e-19 J
e) 6.2947e-18 J; 31.6 nm
f) 2.21e-22 J
g) 7.1e-19 J; 1.1e15 Hz
h) 3.422e-19 J; 581 nm
i) 4.2e14 Hz
j) 1.92e8 m
k) 7.14e16 Hz; Ultraviolet
Explanation:
Frequency: ν Wavelength: λ Energy: E Speed of light: C (3.00e8) Planck's Constant: h (6.626e-34)
ν -> λ λ = C/ν
λ -> ν ν = C/λ
For either of these equations, wavelength must be converted to meters or nanometers, depending on the equation.
For ν -> λ, after doing the equation, convert the wavelength into nanometers by dividing by 1e-9.
For converting λ -> ν, convert the wavelength into meters by multiplying by 1e-9.
For energy: E = hν = hc/λ
Now that the setup is out of the way:
a) Violet light has a wavelength of 4.20 x 10-12 m. What is the frequency?
λ -> ν ν = C/λ
[tex]\frac{3.00e8}{4.20e-12}[/tex] = 7.14e19 Hz
b) A photon has a frequency (n) of 3.468 x 106 Hz. Calculate its energy
E = hν = hc/λ
(6.626e-34) (3.468e6) = 2.298e-27 J
c) Calculate the energy (E) and wavelength (l) of a photon of light with a frequency of 4.215 x 1014 Hz.
E = hν = hc/λ
(6.626e-34) (4.215e14) = 2.793e-19 J
ν -> λ λ = C/ν
[tex]\frac{3.00e8}{4.215e14}[/tex] = 7.117 m
[tex]\frac{7.117m}{1}*\frac{1nm}{1e-9m}[/tex] = 7.117e9 nm
d) Calculate the frequency and the energy of blue light that has a wavelength of 400 nm (h = 6.62 x 10-34 J-s).
λ -> ν ν = C/λ
[tex]\frac{400 nm}{1} *\frac{1e-9m}{1nm}[/tex] = 4e-7 m
[tex]\frac{3.00e8}{4e-7}[/tex] = 7.5e14 Hz
E = hν = hc/λ
(6.626e-34) (7.5e14) = 4.96e-19 J
e) Calculate the wavelength and energy of light that has a frequency of 9.5 x 1015 Hz.
ν -> λ λ = C/ν
[tex]\frac{3.00e8}{9.5e15}[/tex] = 3.16e-8 m
[tex]\frac{3.16e-8m}{1}*\frac{1nm}{1e-9m}[/tex] = 31.6 nm
E = hν = hc/λ
(6.626e-34) (9.5e15) = 6.2947e-18 J
f) A photon of light has a wavelength of 0.090 cm. Calculate its energy.
E = hν = hc/λ
Convert the wavelength from cm to meters:
[tex]\frac{0.090cm}{1} *\frac{1m}{100cm}[/tex] = 9e-4 m
[tex]\frac{(6.626e-34)(3.00e8)}{9e-4}[/tex] = 2.21e-22 J
g) Calculate the energy and frequency of red light having a wavelength of 2.80 x 10-5 cm.
E = hν = hc/λ
Convert the wavelength from cm to meters:
[tex]\frac{2.80e-5cm}{1} *\frac{1m}{100cm}[/tex] = 2.8e-7 m
[tex]\frac{(6.626e-34)(3.00e8)}{2.8e-7}[/tex] = 7.1e-19 J
λ -> ν ν = C/λ
Convert the wavelength from cm to meters:
[tex]\frac{2.80e-5cm}{1} *\frac{1m}{100cm}[/tex] = 2.8e-7 m
[tex]\frac{3.00e8}{2.8e-7}[/tex] = 1.1e15 Hz
h) Calculate the energy (E) and wavelength (l) of a photon of light with a frequency of 5.165 x 1014 Hz.
E = hν = hc/λ
(6.626e-34) (5.165e14) = 3.422e-19 J
ν -> λ λ = C/ν
[tex]\frac{3.00e8}{5.165e14}[/tex] = 5.81e-7 m
[tex]\frac{5.81e-7m}{1}*\frac{1nm}{1e-9m}[/tex] = 581 nm
i) The wavelength of green light from a traffic signal is centered at 7.20 x 10-5 cm. Calculate the frequency.
λ -> ν ν = C/λ
Convert the wavelength from cm to meters:
[tex]\frac{7.20e-5 cm}{1} *\frac{1m}{100cm}[/tex] = 7.2e-7 m
[tex]\frac{3.00e8}{7.2e-7}[/tex] = 4.2e14 Hz
j) If it takes 1.56 seconds for radio waves (which travel at the speed of light) to reach the moon from Earth, how far away is the moon?
All we want to do here is to convert frequency (speed) to wavelength (distance). This problem requires a bit of thought, but it isn't bad once you realize that frquency is speed and wavelength is distance. It becomes just like the other problems after that. Also, I'll leave this distance in meters, but I think you can figure out how to convert it if it wants it in another unit.
One second is equal to 1 Hertz, so our frequency is 1.56 Hz.
ν -> λ λ = C/ν
[tex]\frac{3.00e8}{1.56}[/tex] = 1.92e8 m
The actual distance from the earth to the moon via google is 3.84e7, but sometimes problems like this will mess with the numbers to make sure that you didn't just look up the answer. I'm still pretty sure that this is right, however.
k) Calculate the frequency of light that has a wavelength of 4.20 x 10-9m. Identify the type of electromagnetic radiation.
First, we convert wavelength to frequency, as normal:
λ -> ν ν = C/λ
[tex]\frac{3.00e8}{4.20e-9}[/tex] = 7.14e16 Hz
Then we identify the electromagnetic wave type. You can look up a conversion chart for these on google, but since our frequency is in the e15 - e17 range, this light is considered ultraviolet.
Atoms with a different number of protons than electrons are called:
Answer:
Hello!!! Princess Sakura here ^^
Explanation:
They are called isotopes.
Answer:
A positive ion.
Explanation:
I think
list in the following elements in order of smallest to largest atomic radius. F, Cl, Br, l
And which has a larger atomic radius?
Reggie suddenly decided to drive to the Grand Canyon, because he had never seen it. He didn't even have a map showing him how to get there! Reggie made a(n) _____. a. routine decision b. impulse decision c. daily decision d. regular decision Please select the best answer from the choices provided A B C D
Answer:
b. impulse decision
Explanation:
In this scenario, Reggie suddenly decided to drive to the Grand Canyon, because he had never seen it. He didn't even have a map showing him how to get there! Reggie made an impulse decision.
An impulse decision can be defined as a type of decision an individual makes without having a clear thought about the decision. Thus, an impulsive decision is strictly based on an individual's inclination, instinct, whim or sudden desire to do something.
This ultimately implies that, decisions that are made spontaneously without due diligence and considerations refer to an impulse decision.
Hence, Reginald's decision is an impulse decision because he suddenly decided to drive to go see a place (Grand Canyon) he hasn't seen before, even though he had no map to use as a guide or direction.
Answer: b
Explanation:
Help pleaI’ll give brainliest
Which element has the
greatest number of valence electrons available for bonding?
O selenium
Oboron
O calcium
O chlorine
Identify the reaction type shown and describe the clues that were used to identify it.
Fe2O3 + 2SiO2 → Fe2Si2O7
Jack has a rock.the rock has a mass of 14g and a volume of 2cm^3.what is the density of the rock?
1
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Answer:
7
⋅
g
⋅
c
m
−
3
Explanation:
Please Answer. What is the density of an object that has a mass of 13g and a volume of 25 cm3?
Answer:
The density of object is 0.52 g/cm³
Explanation:
Given data:
Density of object = ?
Mass of object = 13 g
Volume of object = 25 cm³
Solution:
Formula:
d = m/v
d = 13 g/ 25 cm³
d = 0.52 g/cm³
Thus, the density of object is 0.52 g/cm³.
The atomic masses of elements are generally not whole numbers. Explain why.
Answer:
Because elements have isotopes.
Explanation:
So the atomic mass is the average of an element's isotopes.
Answer:
The atomic masses of most elements are not whole numbers, because they are a weighted average of the mass numbers of the different isotopes of that element, with respect to their abundances in nature.
Explanation:
Sodium electron configuration in longhand notation
Answer:
Na₁₁ = 1s² 2s² 2p⁶ 3s¹
Explanation:
Sodium is present in group 1.
It is alkali metal.
It has one valence electron.
The atomic number of sodium is 11.
Its atomic mass is 23 amu.
The longhand notation of electronic configuration of sodium can be written as,
Na₁₁ = 1s² 2s² 2p⁶ 3s¹
The electronic configuration in shorthand notation( noble gas) would be written as,
Na₁₁ = [Ne] 3s¹
Sodium loses its one valence electron to complete the octet and get stable thus form +1 cation.
It react with halogen and form salt. Such as sodium chloride.
2Na + Cl₂ → 2NaCl
what unit of measure would i use to measure the width of my fingernail A millimeters
B centimeters C meters D kilometers
E grams
What happens in the nucleus when a lithium atom becomes an ion
Answer:
An atom that gains a negative electron, it becomes a negative ion. ... A lithium atom has 3 protons and 3 electrons. It can lose one of its electrons, making it an ion. It now has more positive protons than electrons so it has an overall positive charge.
Answer:
This means a Lithium atom formed into a Lithium ion by losing one of its electrons. It has three electrons and three protons to begin with. So when it loses or gains one the amount isnt equal, that is why it becomes an ion. If it gained electrons it would have a negative charge on the nulcleus, though if it lost electrons it would have a positivec charge. Hope this helped!!
what are these significant figs A) 0.0040 B)1,000,000 C) 1.20 X 10^3
Which is a way that the model of the atom became stronger through new experiments? (1 point)
a
New technology allowed scientists to show that the atom is indivisible.
b
It took new data to show that positive charge is not spread throughout an atom.
c
By deflecting alpha particles, Rutherford first observed the neutron.
d
The neutron could not be detected until Cathode–Ray Tubes were invented.
Answer:
Explanation:
Key points
J.J. Thomson's experiments with cathode ray tubes showed that all atoms contain tiny negatively charged subatomic particles or electrons.
Thomson's plum pudding model of the atom had negatively-charged electrons embedded within a positively-charged "soup."
Rutherford's gold foil experiment showed that the atom is mostly empty space with a tiny, dense, positively-charged nucleus.
Based on these results, Rutherford proposed the nuclear model of the atom.
Silver is a white metal that is an excellent conductor. Silver tarnishes when exposed to air and light. The density of silver is 10.49 g/cm3. The melting point is 962oC and the boiling point is 2000oC. A chemical property of silver is A) density. B) melting point. C) tarnishes in air. D) that it is a conductor.
Answer:
c tarnishes in air
Explanation:
After silver has been exposed to air that contains sulphur gases, discoloration would occur. there would be darkening that is caused by the reaction with gases.When any silver object tarnishes, it brings about a disfiguring of that object. Hydrogen sulphide would be needed for this to happen. silver sulphide is black and a if a thin layer should form on any surface, it ill darken it. This is what we refer to as tarnishing.
Answer:
c
Explanation:
it tarnishes in air
1. Using a triple beam balance and a graduated cylinder, a student collected data on a sample of an
element:
Mass of sample - 67.9 g
Volume of water - 52.0 ml
Volume of water and sample - 28.0 ml
a) Calculate the density of the sample. Show all work and use significant figures and units.
Answer:
d = 2.8 g/mL
Explanation:
Given data:
Mass of sample = 67.9 g
Volume of water = 28.0 mL
Volume of water + sample = 52.0 mL
Density of sample = ?
Solution;
Density is equal to the mass of substance over volume of substance.
Formula:
d = m/v
d = density
m = mass
v= volume
Now we will calculate the volume of sample.
Volume of sample = (volume of water+ sample) - volume of water
Volume of sample = 52.0 mL - 28.0 mL
Volume of sample = 24.0 mL
Now we will calculate the density.
d =67.9 g /24.0 mL
d = 2.8 g/mL
in the chemical equation HCI+CaCO3 which element cannot be apart of the products a carbon b chlorine c nitrogen d oxygen
Answer:
Nitrogen
Explanation:
The element nitrogen cannot be a product in the given reaction.
The reaction is;
HCl + CaCO₃
According to the law of conservation of matter, "matter is neither created nor destroyed in the cause of a chemical reaction".
The law suggests that, in a chemical reaction, we end up with the same species we started with. Although due to rearrangement of bonds, new compounds can form;
Starting atoms
H
Cl
Ca
O
These species will also be found in the product.
use the Kinetic Theory to explain the following. when you come home from school and open the door you can smell your tea being cooked
Answer:
Tea is getting hot on the stove.
2) As the tea and water gets hot, some combined molecules of tea and water will escape from the teapot.
3) Those escaped molecules now have the entire free space of the entire room to float around in, which they do (because they have high kinetic energy due to being heated).
4) Hence, in this scenario, your nose will detect a few of those molecules and you smell hot or warm tea.
5) Cold tea would be a different story. Cold beverages like cold tea do not have the kinetic energy where molecules can 'break free' of the surrounding container. Someone could be sitting in the room having a can or bottle of cold tea and you would not notice that when you walked in the door.
Which of these statements describes a chemical property?
Answer:
it rusts when exposed to air
Answer:
A
Explanation:
Do it for 60 points pleaseee
Answer:
period number
Answer:
Period number
Explanation:
Period number is the answer.
Hope this is right!
If an atom has 15 protons and how many electrons will be gained when this atom forms an ion?
Answer:
What are the Answer choices
Is burning the glass plate is physical or chemical change?
PLEASE HELP!
Why do atoms share electrons in covalent bonds?
A. to attain a noble-gas electron configuration
B. to become more polar
C. to become ions and attract each other
D. to increase their atomic numbers
Answer:
Answer Option A) To attain a noble-gas electron configuration.
Explanation:
Correct answer from test
Taking into account the definition of covalent bond and octet rule, the correct answer is option A. Atoms share electrons in covalent bonds to achieve a noble gas electron configuration.
The covalent bond is the chemical bond that occurs between atoms of non-metallic elements. These atoms have many electrons at their outermost level and have a tendency to share them to acquire the stability of the noble gas electronic structure. In this way a molecule is formed.
The tendency of the elements to reach a stable configuration is known as the octet rule. For this, the octet rule explains that there must be eight electrons in their last energy levels, thus acquiring the structure of a noble gas.
So, a covalent bond is a force that joins two atoms of non-metallic elements to form a molecule in order to comply with the octet rule.
Finally, the correct answer is option A. Atoms share electrons in covalent bonds to achieve a noble gas electron configuration.
Learn more:
https://brainly.com/question/14149997?referrer=searchResultshttps://brainly.com/question/12694836?referrer=searchResultshttps://brainly.com/question/2959530?referrer=searchResultsWhich answer choice best explains why nuclear reactions release more energy than chemical reactions? Electrostatic forces of repulsion are thousands of times stronger than gravitational forces. Gravitational forces are thousands of times stronger than electrostatic forces of repulsion. The force that binds together protons and neutrons is stronger than the force that attracts and repels protons and electrons. The force that attracts and repels protons and electrons is stronger than the force that binds together protons and neutrons.
Answer:
The force that binds together protons and neutrons is stronger than the force that attracts and repels protons and electrons.
Explanation:
1. Protons are positively charged. Protons have a mass of 1.
2. Neutrons are uncharged. Neutrons have a mass of 1.
3. Electrons are negatively charged. Electrons have almost no mass.
Nuclear reactions release more energy than chemical reactions as the force that binds together protons and neutrons is stronger than the force that attracts and repels protons and electrons.
Answer:
C) The force that binds together protons and neutrons is stronger than the force that attracts and repels protons and electrons.
Explanation:
When your food gets digested, the macromolecules get broken down into
individual monomers. Which monomer would be most present based on your meal?
How do you know?
Convert 427 Liters of CO2 to moles.
Answer:
9.702450607255294
.....0
In which region is the substance in both the solid phase and the liquid phase?
1 2 3 4
Answer:
its 2 on ed I promise do not listen to the brainiest
Explanation:
Answer:
B)2
Explanation:
which of the following do all living organisms have in common ?