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 number of moles in 4.5 x 10^24 atoms of oxegen is
Answer:
The answer is 7.48 molesExplanation:
To find the number of moles in a substance given it's number of entities we use the formula
[tex]n = \frac{N}{L} \\ [/tex]
where n is the number of moles
N is the number of entities
L is the Avogadro's constant which is
6.02 × 10²³ entities
From the question we have
[tex]n = \frac{4.5 \times {10}^{24} }{6.02 \times {10}^{23} } \\ = 7.47508...[/tex]
We have the final answer as
7.48 molesHope this helps you
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.
Identify the reaction type shown and describe the clues that were used to identify it.
Fe2O3 + 2SiO2 → Fe2Si2O7
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.
Find more information about Oxygen here:
brainly.com/question/26073928
A cup of hot water contains fewer molecules than a tub of hot water. This same cup of hot water will freeze faster than a tub of hot water. The total thermal energy of a system is not only dependent on the state of the material but also on the (resistance, heat, temp, half-life) and the total number of (atoms, currents, compounds, electromagnetic waves) in the system.
Answer:
The correct options are;
1) Heat
2) Atoms
Explanation:
The heat required to raise a unit mass of a substance by one degree which is the specific heat capacity of the substance, is a quantity characteristic of a given substance and the amount of temperature change experienced by the substance when an amount of heat energy transferred to the substance is a function of the mass of the substance, which is a function of the number of atoms present in the substance.
So also, the total thermal energy that is stored by a substance, that causes a given amount of temperature change, is a function of the heat capacity of the substance.
how does litmus indicator work
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.
To learn more about mass, here:
https://brainly.com/question/28704035
#SPJ6
Do 2. A student determines that there are 1.3 x 1025 molecules of an unknown
substance in a 968 g sample. Which compound most likely represents this
unknown substance?
CO
CIO
2)
CO2
N203
CLEAR ALL
Answer:
The correct option is;
CO₂
Explanation:
The given information are;
The number of molecules in the substance = 1.3 × 10²⁵
The mass of the substance = 968 g
Therefore, we have;
The number of molecules in one mole of a substance = 6.02 × 10²³
The number of moles present = (1.3 × 10²⁵)/(6.02 × 10²³) ≈ 21.595 moles
Therefore, 968 g = 21.595 moles
1 mole = 968/21.595 = 44.826 g
The mass of one mole of the substance = 44.826 g
Therefore the mass of one mole of the substance is closely related to the mass of one mole of CO₂ which is 44.01 g/mol.
The correct option is CO₂
The calculation is as follows:The number of molecules in one mole of a substance should be = 6.02 × 10²³
And,
The number of moles present is
= (1.3 × 10²⁵)/(6.02 × 10²³)
≈ 21.595 moles
Now
1 mole = 968/21.595 = 44.826 g
The mass of one mole of the substance = 44.826 g
So, the mass of one mole of the substance is closely related to the mass of one mole of CO₂ i.e. 44.01 g/mol.
Learn more: https://brainly.com/question/1504221?referrer=searchResults
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.
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
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:
what is the name of CCI3
carbon trichlorine????
Carbon tetrachloride, also known by many other names (such as tetrachloromethane, also recognised by the IUPAC, carbon tet in the cleaning industry, Halon-104 in firefighting, and Refrigerant-10 in HVACR) is an organic compound with the chemical formula CCl4.
the making of ice cubes is an endothermic reaction
Answer:
no
Explanation:
it is not endothermic reaction
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.
Learn more about heat energy, here:
https://brainly.com/question/10162784
#SPJ2
Identify the heterogeneous mixtures.
Group of answer choices
salad
water
vegetable soup
apple juice
trail mix
brass
Homer notices that his shower is covered in a strange green slime. His friend Barney tells him that coconut juice will get rid of the green slime. Homer decides to check this out by spraying half of the shower with coconut juice. He sprays the other half of the shower with water. After 3 days of "treatment" there is no change in the appearance of the green
Answer:
This strange green slime is a colonization of fungi caused by the humidity of the bathrooms, which to be eradicated requires a non-specific antimicrobial such as sodium hypochlorite that generates an osmotic imbalance producing a fungicidal effect.
Explanation:
The fungi that appear in the form of slime at the microscopic level have many forms of colonization, by adding coconut milk it was assumed that this would generate an environment not suitable for their metabolism and reproduction but this did not happen, therefore they continued their reproduction.
Answer:
Explain?
Explanation:
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.
A train in Japan can travel 813.5 miles in 5 hours
Answer:
162.7miles/hr
Explanation:
Given parameters:
Distance covered by the train = 813.5miles
Time taken = 5hours
Unknown:
Speed of the train = ?
Solution:
Speed is a physical quantity.
It is mathematically expressed as;
Speed = [tex]\frac{distance}{time}[/tex]
So, input parameters and solve;
Speed = [tex]\frac{813.5}{5}[/tex] = 162.7miles/hr
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
Not all protists use flagella or cilia to move. Give an example of another way protists move and identify the type of protist that uses that mode of movement.
Answer: One of the most striking features of many protist species is the presence of some type of locomotory organelle, easily visible under a light microscope. A few forms can move by gliding or floating, although the vast majority move by means of “whips” or small “hairs” known as flagella or cilia, respectively. (Those organelles give their names to informal groups—flagellates and ciliates—of protists.) A lesser number of protists employ pseudopodia. Those same organelles may be used in feeding as well.
Explanation:
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:
Name for each compoud
1.CO
2.H2SO4
3CaCO3
4 H202
5NaF
How to separate these pure substance?if it is not possible, please write cannot be separate
Oxgen
Water
Gold
Carbon Dioxide
Carbon
Answer:
Oxgen- cannot be separated
Water - chemical change
Gold - cannot be separated
Carbon Dioxide - chemical change
Carbon - cannot be separated
Explanation:
A pure substance, which can either be an element or a compound, contains only one type of such element or compound. In opposition to a mixture, pure substances cannot be separated by physical means.
- Elements as a pure substance cannot be separated because it contains only one type of atom. However, compounds contain two or more types of atoms, and hence, can only be separated into its individual atoms via chemical means.
In this question, oxygen (O2), Gold (Au) and carbon (C) are all elements and hence cannot be separated. Carbon dioxide (CO2) and water (H2O) are compounds because they contain two different atoms respectively, hence, can be separated into individual atoms.
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]
Which pair of symbols represents nuclei with the same number of neutrons?
A. 56 Co and 580
B. 57Co and 58Ni
c. 57Fe and 58 Ni
D. 57Mn and 57Fe
Answer:
B
Explanation:
Mass number = number of neutrons + number of protons
Atomic number is the number of protons in the nucleus.
58Ni : 58 is the number of neutrons + number of protons
atomic number of Ni is 28. Thus, 58 -28 = 30 neutrons
57Co ; 57 is the number of neutrons + number of protons
number of Co is 27. Thus, 57 – 27 = 30 neutrons
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
After lab, all of Darrel's friends looked at his data and laughed and laughed. They told him that he was 30.8% too low in the boiling point he had just recorded. He had recorded a boiling point of 50o C on his data sheet. What is the correct boiling point of the liquid he was working with in lab?
Answer:
100°
Explanation:
For a boiling point is it always 100°
Is burning the glass plate is physical or chemical change?
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