Answer:
95% of the time (or any other percentage you choose), the electron will be found within a fairly easily defined region of space quite close to the nucleus. Such a region of space is called an orbital. You can think of an orbital as being the region of space in which the electron lives
How many moles are in a sample of 2.39 x 10^23 atoms of sodium (Na)
Answer:
The answer is 0.4 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{2.39 \times {10}^{23} }{6.02 \times {10}^{23} } \\ = 0.39700996...[/tex]
We have the final answer as
0.4 molesHope this helps you
Rubbing alcohol or isopropanol can be described by the chemical formula C3H7OH. One milliliter of isopropanol has a mass of 0.76 g, so its density is 0.76 g/mL. Isopropanol is often used as a cleaner or a disinfectant and evaporates when placed on warm objects. However, caution must be taken when using isopropanol, because it is also highly flammable. Which of the following is a chemical property of isopropanol?
A. One mL of isopropanol has a mass of 0.76 g.
B. Isopropanol has a density of 0.76 g/mL.
C. Isopropanol evaporates when placed on a warm object.
D. Isopropanol is flammable.
A chemical property of isopropanol : D. Isopropanol is flammable.
Further explanationThere are changes that occur in the mater: physical changes and chemical changes
Classification uses the principle of the initial and final state of the substance.
Physical changes do not form new substances, so the properties of the particles remain the same.(size,volume,shape)
Example : boiling and freezing, just change its phase form from liquid to gas or from liquid to solid
Chemical changes/reaction form new substances(products) that are different from the initial substances(reactants)
Example : toxic, corroded
So :
the physical properties of isopropanol :mass, density, evaporation
the chemical properties of isopropanol :highly flammable
Answer:
D. Isopropanol is flammable.
Explanation:
Mass, volume, temperature, phase of matter, color, texture, density, and hardness are all examples of physical properties. However, flammability is an example of a chemical property.
Chemical properties describe an object's potential to change its chemical composition. These properties depend on the types of atoms found in the object and the arrangement of those atoms (and their subatomic particles).
A balloon is a sphere with a radius of 5.0 m. The force of air against the walls of the balloon is 45 N. What is the air pressure inside the balloon? Surface area = 12.56 × radius² 1 Pa = 1 N/m² How would I solve this problem? What are the steps or a good way to remeber how to solve?
Answer:
0.127 N/m² or 0.127 Pa
Explanation:
From the question given above, the following data were obtained:
Radius (r) = 5 m
Force (F) = 40 N
Pressure (P) =.?
Next, we shall determine the Surface area of the sphere (i.e the balloon). This can be obtained as follow:
Surface area = 12.56 × r²
Radius (r) = 5 m
Surface area = 12.56 × 5²
Surface area = 12.56 × 25
Surface area = 314 m²
Finally, we shall determine the pressure as follow:
Force (F) = 40 N
Surface area = 314 m²
Pressure (P) =.?
Pressure = Force /Area
Pressure = 40/314
Pressure = 0.127 N/m² = 0.127 Pa
Therefore, the pressure inside the balloon is 0.127 N/m² or 0.127 Pa.
Scientists and nutritionists have long suspected that high-fructose corn syrup, used to
sweeten soft drinks, is one of the causes of childhood obesity. In a recent study, at the
University of Cincinnati, researchers found that mice that drank water with added
fructose ate less solid food, gained more weight, and put on 90% more body fat than
mice that drank only water. Scientists concluded that fructose may affect metabolism in
a way that favors fat storage.
What is the independent variable?
The mice that drank only water
The presence of fructose in their diet
The quantity of water provided
The weight gained by the mice
Answer:
The presence of fructose in their diet
Explanation:
The independent variable in an experiment is the type of variable which is changed at intervals in order to study if it has a direct effect on the dependent variable.
The dependent variable in the experiment is the amount of weight gained by the mice in each group and the control group is the mice who drank the water without the fructose added.
You are conducting an experiment with two very reactive substances. One will react with oxygen (O) and other substances in the air, and the other will react to metal in a container. What type of environment can you seal them in so they only react with each other?
Answer:
seal them in a glass container in an atmosphere of argon (Ar) gas
Explanation:
What is the mass of an object with a density of 5.7 g/cm^3 and a volume of 48
cm^3? *
Answer:
273.6 g
Explanation:
mass =(density)(volume)
mass=(5.7g/cm^3 )(48 cm^3)
cancel out your cm^3 and your are left with grams
multiply (5.7g)(48)=273.6 g
The mass of an object with a density of 5.7 g/cm³ and a volume of 48 cm³ is 273.6 grams.
What is density?Density is defined as the degree to which a material is packed together.
It is also defined as a mass per unit volume of the substance.
Its SI unit is kilogram per cubic meter or gram per meter.
Density can be expressed as
Density = mass / volume
Mass = density x volume
As given, Density = 5.7 g/cm³
Volume = 48 cm³
So, Mass = 5.7 g/cm³ x 48 cm³
= 273.6 grams
Thus, the mass of an object with a density of 5.7 g/cm³ and a volume of 48 cm³ is 273.6 grams.
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Calculate the heat that must be supplied to
a 532 , stainless steel vessel containing 375 g
of water to raise its temperature from 35 C
to the boiling point of water 100°C. Cs. =0.51 J/g. degrees C
Answer in units of J.
Q must be supplied = 119523.3~J
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 in = Q out
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
So from the question :
Q to the system(Q supplied) = Q water + Q steel vessel(Q gained)
[tex]\tt Q~supplied=m.c\Delta T(water)+m.c\Delta T(vessel)\\\\Q~supplied=375\times 4.18\times (100-35)+532\times 0.51(100-35)\\\\Q~supplied=101887.5+17635.8=119523.3~J[/tex]
When many earthquakes are studied, there is another common pattern that emerges: a "Shadow Zone". This is an area, for any earthquake, on the Earth where direct S-waves don't arrive at all and P waves are refracted. What do you think causes these P waves to be refracted? *
Answer:
Sudden decrease in the velocity at the boundary.
Explanation:
The shadow zone is the zone of the earth from angular distances of 104° to 140° from a known earthquake that does not directly receive any P waves. Now, this shadow zone occurs as a result of S waves getting stopped completely by the liquid core and the P waves being refracted by the liquid core.
From earlier seismic discoveries, this boundary which is the shadow zone that does not directly receive any P-waves was found to be due to the fact that the P-waves were refracted inwards as a result of the sudden decrease in velocity at the boundary.
Calculate the volume 3.00 moles of a gas will occupy at 24.0 °C and 762.4 mm Hg.
Answer:
Use formula of PV = nRT
Change formula to solve for Volume = nRT/P
R is a constant 0.08206
Convert C to Kelvin which is just +273
And turn mmHg into atm which is around 1 atm
Plug in and solve
stages of mitosis in order
Answer:
nucleus formed
prophase
metaphase
anaphase
telophase and cytokinesis
What is a system?
A. An isolated piece of the world
OB. A liquid in which reactions take place
O C. A piece of scientific equipment
O D. A technique for recording data
Answer:
D. a technique of recording data
Which has a smaller ionic radius than it's neutral atom?
A. Iodine
B.Cesium
C.Oxygen
D.Nitrogen
Explanation:
Caesium (Cs) has a smaller ionic radius than it's neutral atom.
because Caesium belong to Group 1 and It loses 1 electron. After losing 1 electron it gains 1 positive charge that's why caesium ionic radius become smaller as compared to neutral atom.
Therefore,
Option B is correct.
ANSWER ASAP PLEASE!!
What determines how many of each ion is required for an ionic compounds?
please do not look up on google!!!!
Each ion has a single charge, one positive and one negative, so we need only one ion of each to balance the overall charge. When writing the ionic formula, we follow two additional conventions: (1) write the formula for the cation first and the formula for the anion next, but (2) do not write the charges on the ions.
Which of the following is the correct model of C7H16?
A.
B.
C.
D.
Answer:
D
Explanation:
Option D gives the correct model of C7H16. From the option, one will discover that the model has 7 carbons in the backbone. If you count the attached hydrogen, you will discover that the hydrogen is 16 in total.
This model or skeletal structure of this element represents heptane. Heptane or n-heptane is known to be a straight-chain compound and an alkane. It's chemical formula can also be written as: H₃C(CH₂)₅CH₃ or C₇H₁₆.
This compound is known to be one of the main components of gasoline. It is known to be a volatile organic compound and a clear and colorless liquids with a petroleum-like odor.
Answer: D
Explanation: Just took the test
Help ASAP!!!! Plz!!!!!!!
If a wave of red light has a wavelength of 6.7 x 10-7 m, will the frequency of the red wave be high or low?
Answer:
Its high
Explanation:
Becuase if u times it what do u get
Volcanic belts form along
a.
islands in the Pacific Ocean.
b.
North American mountain ranges.
c.
the boundaries of Earth’s plates.
d.
the coast of Antarctica.
Please select the best answer from the choices provided
How does the valence electron configuration (entire last energy level configuration) relate to the group number on the Periodic Table? Use the shorthand notation in your discussion.
Answer:
The valence electron configuration determines the group to which an element belongs to.
Explanation:
The valence electron configuration of an atom of an element refers to the number of electrons in that atoms outermost shell.
The valence electron configuration is related to the group number of an element in that the number of electrons in the valence shell of an atom of an element determines the group to which an element belongs to. For example, all elements having one valence electron belong to group IA of the periodic table. Similarly, all elements having seven valence electrons belong to group VIIA of the periodic table.
This is because, since the reactivity of an element is related to its ability to either gain or lose a certain number of electrons in its valence shell, elements having same number of valence electrons have similar chemical properties.
A total of eighteen electrons can be placed into the 3rd energy level.
Explain WHY?
Answer:
each principal energy level above the second contains, in addition to one s orbital and three p orbitals, a set of five d orbitals, called the d sublevel. The five d orbitals can hold up to 10 electrons. Thus, the third level holds a maximum of 18 electrons: 2 in the s orbital, 6 in the three p orbitals, and 10 in the five d orbitals.
Explanation:
What explains the structure of metals and delocalized electrons?
A. the unit cell model
B. the geometric shape model
C. the covalent bond model
D. the electron sea model
What occurs to the particles in a fluid during convection ?
Answer: what are options
Explanation:
25 cm of liquid 'A' and 20 cm of liquid
'B' are mixed at 25°C and the volume of
solution was measured to be 44.8 cm3
then correct reaction is
(A) A Hmix = 0, solution shows
ideal
Answer:
The correct option is;
(B) [tex]\Delta H_{mix} < 0[/tex], solution shows negative deviation
Explanation:
The given parameters are;
The available volume of liquid A = 25 cm³
The available volume of liquid B = 20 cm³
The volume of the solution (mixture) = 44.8 cm³
Therefore, we have;
[tex]\Delta _{mix} V < 0[/tex]
Which is one of the prerequisite for the formation of negative deviation
When a non-ideal solution shows negative deviation according to Raoult's Law, we have;
[tex]\Delta _{mix} H < 0[/tex], we have more heat released due to new molecular interactions.
Which refers to a method that relies on sound waves and is used by different animal species for navigation,
communication, and finding food?
echolocation
analog signaling
infrared detection
o digital location
HELP FAST ILL MARK BRAINLEST
Answer:
A
Explanation:
got it on edge
An echolocation refers to a method that relies on sound waves and is used by different animal species for navigation, communication, and finding food. Therefore, option A is correct.
What is an echolocation ?Echolocation is a method used by bats, dolphins, and other animals to locate objects using reflected sound. This enables the animals to move around in complete darkness, allowing them to navigate, hunt, recognize friends and enemies, and avoid obstacles.
(1) To hunt for prey, bats make high-frequency sounds. (2) Sound waves are used by dolphins and other toothed whales to locate prey and navigate their surroundings. (3) Nocturnal oil birds use echolocation to navigate their surroundings, particularly in low-light conditions.
Echolocation is used to help with orientation, obstacle avoidance, food acquisition, and social interactions.
Thus, option A is correct.
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You have a solution of water and pure ethanol. The boiling point of water is 100 degrees Celsius and the boiling point of pure ethanol is 78 degrees Celsius. A. What process would you would use to separate this solution? Describe, in detail, how this process works.
Answer:
Distillation
Explanation:
A solution of water and ethanol are miscible. Hence, they can only be separated by a process known as distillation. Distillation is the process in which two or more constituents in a mixture are separated based on there difference in boiling points. The mixture is subjected to high heat and the one with the least boiling point distills/evaporates out first followed by the next least boiling point.
From the explanation above, it can be deduced that ethanol (with boiling point of 78°) will be distilled out while water remains in the boiling tube or container.
What kinds of paintings did Winslow Homer make
Why are biopharmaceuticals in high demand?
Answer:
the market is largely driven by the growing population, increasing burden of chronic disease, and rising inclination toward targeted therapy.
Explanation:
also, the huge demand of biopharmaceutical is facilitated by an accelerating focus in research and related investment.
Which types of matter are made of atoms
a. Mixtures
b. Elements
C. Compounds
D. All of the above
Answer:
D all above yes I think it's all above
Answer: D
Explanation: All of the above.
Plz mark brainliest:)
colonel flanders makes boxes of chicken with various numbers of pieces. He charges $ 0.40 for each piece of chicken, plus a fixed charge of $ 0.55 for the box, the rolls, etc. If Iddy Ottic bought the $6.95 box, how many piecesof chicken should the box contain?
What is the atomic number of an atom?
O the number of neutrons
O the number of electrons and neutrons
O the number of protons
the number protons and neutrons
Identify the property of the matter described below.
Alcohol floats on top of the water.
A-pH
B-conductivity
C-density
D-luster
Answer: C.
Explanation: Alcohol floats on oil and water sinks in oil. Water, alcohol, and oil layer well because of their densities, but also because the oil layer does not dissolve in either liquid. The oil keeps the water and alcohol separated so that they do not dissolve in one another. ... Water sinks because it is more dense than oil.