Answer:
B
Explanation:
Scientists have changed the model of the atom as they have gathered new evidence. One of the atomic models is shown below. A purple center outlined in black with two concentric black circles around the center, the inner circle having 2 small green balls on it and the outer circle having 8 small green balls on it. What experimental evidence led scientists to change from the previous model to this one? A few of the positive particles aimed at a gold foil seemed to bounce back. The colors of light emitted from heated atoms had very specific energies. Experiments with water vapor showed that elements combine in specific proportions. Cathode rays were bent in the same way whenever a magnet was brought near them.
Answer:
B: The colors of light emitted from heated atoms had very specific energies.
Explanation:
dont know if its the same question i had on edg but i think its B. Sorry if i didnt understand the question :)
Answer:
b
Explanation:
The first chemists, philosophers like, Aristotle were from which country?
Answer:
greece
Explanation:
aristole was particularly from stagria, greece. but most early philosophers are from greece
The diagram shows a model of an animal cell. Explain how you'd modify the model to show the structures in a plant cell.
Answer:to show the structures of a plant cell,add a cell wall around the membrane and increase the size of the vaculoe insidethe cell, draw green ovals to represent chloroplasts.
Explanation:
Is the study of the living plants and animals in the ocean
Answer:
marine biologist
Explanation:
marine biologist
Answer:
marine biologist a scientist who studies creatures that live in ocean water, from bacteria and shellfish to kelp and whales. mean One of several measures of the “average size” of a data set. .organism Any living thing, from elephants and plants to bacteria and other types of single-celled life.
What is Chlorofluorocarbons?
Answer:
Chlorofluorocarbons and hydrochlorofluorocarbons are fully or partly halogenated paraffin hydrocarbons that contain only carbon, hydrogen, chlorine, and fluorine, produced as volatile derivative of methane, ethane, and propane. They are also commonly known by the DuPont brand name Freon.
Explanation:
Answer:
Explanation: Chlorofluorocarbons and hydrochlorofluorocarbons are fully or partly halogenated paraffin hydrocarbons that contain only carbon, hydrogen, chlorine, and fluorine, produced as volatile derivative of methane, ethane, and propane. They are also commonly known by the DuPont brand name Freon
hope that helps.↑A substance can change into a new kind of molecule when:
Answer:
Chemical changes cause a substance to change into an entire substance with a new chemical formula. Chemical changes are also known as chemical reactions. The “ingredients” of a reaction are called reactants, and the results are called products.
Hope it helps
A cube of metal has a mass of 5.05 x 10°g and its density is known to be 12.77 g/mL, what is the volume of this metal?
A 395.5 mL
B. 2.529 mL
C. 63,910 mL
D. 64.48 ml
Answer:
Explanation:
option A is correct
5. The diagram above shows what happened when an irregular solid was immersed in water. This irregular solid has the same mass as a gold block, which is 2 cm wide by 2 cm high by 5 cm long. Using the method described in the passage, compare the density of the unknown with the density of gold.
A. Equal to gold
B. Less than gold
C. Greater than gold
D. Cannot be determined
The density of the unknown will be greater than the density of gold.
An overview will be given since the diagram isn't given. The formula to calculate the density of an irregular shape will be the mass divided by the volume.
The density is the mass per volume. From the information given, since they've the same mass, then it means that the volume of the gold will be more than the volume of the unknown. Therefore, the density of the unknown will be greater than gold.
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348 g of water starting at 4.0°Celsius is heated until his temperature is 37°Celsius. Calculate the amount of heat energy needed to cause this rise in temperature
STEP BY STEP EXPLANATION!!
Answer:
48.049 kJ or 48049 J
Explanation:
Hello again.
So we know the formula [tex]q = mc\Delta t[/tex]. c is the heat capacity but this time, it is not given. However, water has a very well known heat capacity which is 4.184 J/(g°C). This is in fact the number we refer to a calorie which is the amount of energy you burn that can raise the temperature of 1g of water by 1°C. So, plugging in values, you get the above. But double check if I am wrong.
The amount of heat energy needed to cause this rise in temperature is 48.049 kJ or 48049 J.
What is heat energy?Heat is the energy that moves from one body to another when temperatures are different. Heat passes from the hotter to the colder body when two bodies with different temperatures are brought together.
A given amount of matter's heat capacity is the amount of energy needed to raise its temperature by one degree Celsius.
The heat energy will be calculated by the formula
Q = m•C•ΔT
Where c is the heat capacity.
The m is the mass
T is the time
Mass is 348 grams
Temperature is 37°C
The change in temperature is 4.0°C to 37°C
The heat capacity of water is 4.184
Q = 348 x 4.184 x -33 = 48049.056.
Therefore, the amount of heat energy needed is 48.049 kJ or 48049 J.
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How many carbon atoms are there in 2.23 grams of propane (C3H8)?
Answer:
3.05x10²³ (3 sig. fig.)
Explanation:
Propane (C₃H₈) is a colorless alkane gas with three carbons and eight hydrogen atoms. In 2.23 grams of propane, there are 3.05 x 10²³ carbon atoms present.
What is the number of particles/atoms?
The number of atoms or the particles being the smallest units is estimated by the product of the number of moles and Avogadro's number.
The Avogadro's number (Na) is used to determine the number of particles that have been present in a mole of a substance. A mole of a substance is said to have 6.022 × 10²³ ions, atoms, electrons, molecules, etc.
Moles of propane are calculated as,
Moles = mass ÷ molar mass
= 2.23 ÷ 440.094
= 0.05057
Now, the number of particles is calculated as,
Number = moles × Avogadro's number
= 0.05057 × 6.022 × 10²³
= 3.05 x 10²³
Therefore, 3.05 x 10²³ carbon atoms are present in 2.23 grams of propane.
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Identify the heterogeneous mixtures.
Group of answer choices
salad
water
vegetable soup
apple juice
trail mix
brass
What is the mass, in grams, of 0.450 moles of Sb?
Answer:
54.9 g
Explanation:
0.450 mol x 122g/mol
Relative and average atomic mass both describe properties of an element related to its different isotopes. Out of these two Relative atomic mas is more accurate. Therefore, 54.9 g is the mass in grams of 0.450 moles of Sb.
What is mass?Mass defines the quantity of a substance. It is measured in gram or kilogram. Average mass is the mass of atoms of an element that are isotopes. It can be calculated by multiplying mass of a isotope to natural abundance of that isotope.
Average atomic mass = (mass of first isotope× percent abundance of first isotope)+(mass of second isotope× percent abundance of second isotope)
Mass of Sb= number of moles of Sb ×Molar mass of Sb
=0.450 mol x 122g/mol
=54.9 g
Therefore, 54.9 g is the mass in grams of 0.450 moles of Sb.
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Radon-222 is an alpha emitter with a half life of 3.82 days.
1. What is the mass number of the daughter isotope?
2. What is the element symbol of the daughter isotope?
3. What is the atomic number of the daughter isotope?
The daughter isotope (a decay product): Polonium (Po)
Further explanationRadioactivity is the process of unstable isotopes to stable isotopes by decay, by emitting certain particles,
alpha α particles ₂He⁴ beta β ₋₁e⁰ particles gamma particles γ positron particles ₁e⁰
Radon-222 emits alpha α particles ₂He⁴ , so the atomic number decreases by 2, mass number decreases by 4
Reaction
[tex]\tt _{86}^{222}Rn\Rightarrow _{84}^{218}+_2^4He[/tex]
1. The mass number of the daughter isotope = 218
2 and 3. If we look at the periodic system, the element with atomic number 84 is Polonium (Po)
Planets A and B are both the same size, but planet B has three times the mass of planet A. How does the weight of an object compare on the two planets?
Choose the correct answer.
The weight of an object is the same on both planets.
The weight of an object is three times larger on planet A.
The weight of an object is three times larger on planet B.
The weight of an object will depend on more factors than just the weight and size of the planet.
Answer:
The answer is d
Explanation:
When we mixed milk and vinegar in the lab demonstration, a/an __.
was created.
Answer:
Plastic
Explanation
Found on google
Synthesis
1 point
Balance the following chemical equation. What are the final coefficients
starting from the left and going to the right? *
AICI:
+
H2O
_Al(OH)3 +
НСІ
1,1,1,1
1, 2, 1, 2
2, 2, 2, 2.
1,3,1,3
Answer:
nãosecoi m fazoe isrspoo rqe a perugtunat iomkplnetacá
Explanationveja qeuastã onvamoetn e depois recoepe-a qui aipis onãestoácpletoma :
explanation of atomic radius
Ah yes.
The atomic radius is basically the distance between the nucleus of the atom and the outermost electron in the farthest orbital of the atom. The more bigger the atomic radius , the less powerful is the force that holds together the nucleus and its electrons.
6. Now, revise your definition for waves to include energy and matter.
A wave is a phenomenon that...
Answer:
A wave is phenomenon that transfers energy from one point to another through a disturbance without affecting the matter.
Explanation:
A wave is phenomenon that transfers energy from one point to another through a disturbance without affecting the matter.
There are two main types of waves Longitudinal waves travels parallel to their source. For example, sound waves. Through a series of rarefactions and compressions, longitudinal waves are propagated. Transverse waves travel perpendicular to their source.Which of the following is true about metals?
A. They are usually less reflective in luster than metalloids.
B.
They are usually better conductors than nonmetals.
C. They are usually less malleable than nonmetals.
D.
They are usually more brittle than metalloids.
HELP!! URGENT ASAP!! WILL GIVE BRAINLIEST TO FASTEST ANSWER!!
Answer:
This shoes the soda lime defusing to limewater turning into germinating seeding which defuses back to limewater
Explanation:
after eating an apple and levaing it on top of the table. what will happend to the color of the inner part of the apple? what makes the color of the apple change
Answer:
Answer Below
Explanation:
When you leave an apple on a table outside it will turn brown. This happens because when you cut an apple, you are exposing it's insides to the oxygen in the air. This causes the PPO (polyphenol oxidase) enzyme in the apple's flesh to oxidize the polyphenols, turning them into some other brown colored products. Hence, the color change.
Answer:
brown i can't explain because its a matter of the atoms in the apple mixing with the air and apple is made with nitrogen
will give brainlliest
Which noble gas is closest to sulfur, S, on the periodic table? What has to happen for a sulfur atom in order to have an electron arrangement similar to the nearest noble gas?
Answer: argon
What must happen to a sulfur atom in order for it to have an electron arrangement similar to that of a noble gas? Answer: The noble gas closest to sulfur is argon. A sulfur atom gains two electrons to have an electron arrangement similar to that of argon.
Explanation:
what is atomic radius
Explanation:
The atomic radius of a chemical element is a measure of the size of its atoms, usually the mean or typical distance from the center of the nucleus to the boundary of the surrounding shells of electrons. Since the boundary is not a well-defined physical entity, there are various non-equivalent definitions of atomic radius. Three widely used definitions of atomic radius are: Van der Waals radius, ionic radius, and covalent radius
Which element is this.Its shiny,Is solid at room temperature, has atoms with two valence electrons?A:Lithium B:Strontium C:Aluminium D:Silicon
Answer:
Strontium
Explanation:
STRONTIUM
Strontium is a chemical element that is non radioactive and its occur naturally. It is a shiny and silvery white metal that have atomic number of 38 and it belong to group 2 member of the periodic table which is why it have two valence electrons. It is a solid metal at room temperature.
About 99% of Strontium is found in bones. It help to make new bones in humans by replacing the old bones.
Therefore, it is strontium.
Strontium is the element which is shiny, solid at room temperature and has two electrons in its outermost shell.
The atomic number of Strontium is 38. In the first shell, there are two electrons, in the second and fourth shell has space for 8 electrons so these shells are filled with electron whereas third shell has 18 electrons and the fifth shell has 2 electrons. Strontium belongs to second group i.e. alkaline earth metals due to which it has two valance electrons in its outermost shell.
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with of the following describe a chemical change
a) a metal fork was melted
b) a metal fork was cut in half
c) a metal fork became bent
d) a metal fork became rusted
Answer:
D
Explanation:
Rusting is a chemical change that occurs due to oxygen.
Answer:
d i had this your welcome
If an animal is placed into a sealed container for a short time, the oxygen level will
A. decrease and the carbon dioxide level will increase.
B. decrease and the carbon dioxide level will decrease,
C, increase and the carbon dioxide level will increase.
D. decrease and the carbon dioxide level will stay the same.
E increase and the carbon dioxide level will decrease.
Answer:
A
Explanation:
Animals take in oxygen and convert it into carbon dioxide therefore the oxygen levels will decrease and the carbon dioxide levels will increase
If an animal is placed into a sealed container for a short time, the oxygen level will: decrease and the carbon dioxide level will increase.
What happens to oxygen level inside a container:The oxygen held inside the space is quickly being consumed by the freight or because of rusting inside a space, and that encased spaces must consistently be treated as perilous. And the carbon dioxide levels on the other hand will increase.
It will not take a long time for an animal to survive under these conditions.
Thus. option A is correct.
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how many picoliters are in 3.16 mL
Answer:
3.16×10⁹ pL
Explanation:
Given data:
Volume in mL = 3.16
Volume in picoliters = ?
Solution:
Picoliter and milliliters are units of volume. Milliliter is greater unit than picoliter.
1 mL = 10⁹ pL
Now we will convert the 3.16 mL into pL.
3.16 mL × 10⁹ pL/ 1 mL
3.16×10⁹ pL
A student lives in an apartment complex next to a park and train tracks. The student observes that they can hear the train coming sooner and from farther away when they are in front of their apartment and can only barely hear the train when they are in the park despite both being the same distance from the railroad tracks.
The student developed the model above. Using the model, identify two potential wave phenomena that occur and are the reason behind why the student can only hear the train in front of the apartment complex.
A.
The train can be heard more easily in front of the apartment complex because of reflection and interference. As the sound comes from the train, the sound waves reflect off of the complex and interfere with each other increasing the amplitude of the wave to make it easier to hear.
B.
The train can not be heard as easily in the park because of reflection and diffraction. The sound reflects off of the trees in the park and diffract between the trees, this causes the waves to bend too much to be heard.
C.
The train can be heard more easily in front of the apartment complex because of diffraction and refraction. The sound waves diffract between the other buildings aiming them towards the apartment complex and then the sound refracts through the apartment complex which makes it more difficult to hear in the park.
D.
The train can not be heard as easily in the park because of interference and reflection. The other buildings in front of the park cause interference of the sound waves from the train and the trees in the park cause reflection making it too hard to hear the train.
Answer:
The answer is A
Explanation:
Please help!!!
When 38 g of a metal at 92 °C is added to
43 g of water at 22°C, the temperature of the
water rises to 30°C. What is the specific heat
capacity of the metal? Assume no heat was
lost to the surroundings.
Answer in units of
J/g degrees C
The specific heat capacity of the metal : 0.610 J/g° C
Further explanationThe law of conservation of energy can be applied to heat changes, i.e. the heat received/absorbed is the same as the heat released
Q abs = Q received
Heat can be calculated using the formula:
Q = mc∆T
Q = heat, J
m = mass, g
c = specific heat, joules / g ° C
∆T = temperature difference, ° C / K
∆T = T(final temp) - T(initial temp)
mass of metal = 38 g
T initial metal = 92 °C
mass of water = 43 g
T final water = 30 °C
T initial water = 22°C
c water = 4.18 J/g° C
Heat absorbed by water[tex]\tt Q=m.c.\Delta T\\\\Q=43\times 4.18\times (30-22^oC)\\\\Q=1437.92~J[/tex]
the specific heat capacity of the metalQ water = Q metal
[tex]\tt 1437.92=38\times c\times (92-30)\\\\c=0.610~J/g^oC[/tex]
How many electrons are there in the only energy level of helium, a noble gas? * Two Three Six Eight
Answer:
Explanation:
Noble gases are the least reactive of all known elements. That's because with eight valence electrons, their outer energy levels are full. The only exception is helium, which has just two electrons.