Answers
Related Questions
choose the letter that best describes the behavior of a substance during a phase change:
/A/ neither absorbs or releases energy
/B/ always absorbs energy
/C/ always releases energy
/D/ either absorbs or releases energy
Answers
Answer:
/D/ either absorbs or releases energy
Explanation:
During a phase change energy is either absorbed or released.
A phase change is a reversible process which occurs when a substance changes is its state from one form to another.
Phase changes are used to delineate physical changes.
A phase diagram provides a graphic representation of the change. The diagram can be 2 dimensional or 3 dimensional.How many electrons are there in the only energy level of helium, a noble gas? * Two Three Six Eight
Answers
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.
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
Answers
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.
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?
Answers
Answer:
seal them in a glass container in an atmosphere of argon (Ar) gas
Explanation:
What suprising result is explained using this model
Answers
Answer:
B. A few positive particles bounced back because they were pushed away from the positive center.
Explanation:
The result of the experiment conducted by Rutherford shows that a few positive particles bounced back because they were pushed away from the positive center.
This is the central theme of Rutherford's experiment on a thin gold foil.
In 1911, Rutherford performed the gold foil experiment that gave the modeling of the atomic structure a great boost. He bombarded a thin gold foil with alpha particles. He discovered that most of the alpha particles passed through the foil while a few of them were deflected back. This led him to postulate that an atom has a small positively charged center where nearly all the mass is concentrated.Does the use of lithium cause human health problems?
Answers
Answer:
Yes
Explanation:
Lithium can cause nausea, diarrhea, dizziness, change in heart rhythm, muscle weakness, fatigue, and a dazed feeling
Continued use of Lithium could mean fine tremor, frequent urination, and thirst
Source: Webmd.com
What is the decomposition of 2LiCIO3
Answers
2LiClO3 —> 2LiCl + 3O2
Name for each compoud
1.CO
2.H2SO4
3CaCO3
4 H202
5NaF
Answers
2. Sulfuric acid
3. Calcium carbonate
4. Hydrogen peroxide
5. Sodium fluoride
hope this helps (:
Identify the heterogeneous mixtures.
Group of answer choices
salad
water
vegetable soup
apple juice
trail mix
brass
Answers
so heterogeneous mixture is would be salad, vegetable soup, trail mix and brass.
this is because salad, vegetable soup, trail mix, and brass have a lot components and they’re not pure.
Hopefully i could help!!
Which describes the elements in a given group of the periodic table?
They decrease in atomic mass as you go down the column.
They increase sequentially in atomic number from top to bottom.
They are in the same family, with similar characteristics.
Their properties change according to a pattern as you go down the column.
Answers
Answer:
They are in the same family, with similar characteristics.
Explanation:
The elements in a given group of the periodic table are in the same family and with similar characteristics.
Vertical columns on the periodic table are referred to as a group or family. Elements having the same number of electrons in the outermost shell of their atoms are placed one another in vertical columns. Each resulting vertical column is a group or family. Elements in the same group exhibit similar chemical properties because of the same number of electrons in their atoms' valence shells.6. Now, revise your definition for waves to include energy and matter.
A wave is a phenomenon that...
Answers
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.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.
Answers
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 train in Japan can travel 813.5 miles in 5 hours
Answers
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
How many atoms are in the following formula?
3Al2O3
Answers
Answer:
15 atoms total
Explanation:
2 Al atoms + 3 O atoms = 5 Al2O3 atoms
5 Al2O3 atoms * 3 = 15
another way to do it is:
2 Al atoms * 3 = 6 Al atoms
3 O atoms * 3 = 9 O atoms
6+9 =15 atoms total
The number of atoms in the given 3Al₂O₃ is 15 atoms.
What are atoms?Atoms are the smallest unit of every matter. It contains charged particles present inside the atoms. They are electrons, protons, and neutrons. Atoms are of four types, description, isotopes, radioactive, and ions.
These atoms are the ions, that are charged, and the charged ions make bonds with each other to form compounds. Aluminum oxide is a compound that is formed by combining aluminum and oxygen atoms.
The compound is 3Al₂O₃
This means there are three moles of aluminum, and three moles of oxygen.
2 Al atoms + 3 O atoms = 5 Al₂O₃ atoms
5 Al₂O₃ atoms x 3 = 15
The elaborative way is:
2 Al atoms x 3 = 6 Al atoms
3 O atoms x 3 = 9 O atoms
6 + 9 =15 atoms total
Thus, the number of atoms is 15 atoms.
To learn more about atoms, refer to the link:
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ANSWER ASAP PLEASE!!
What determines how many of each ion is required for an ionic compounds?
please do not look up on google!!!!
Answers
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.
How many moles are in a sample of 2.39 x 10^23 atoms of sodium (Na)
Answers
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
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.
Answers
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:
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
Answers
Answer:
Explanation:
option A is correct
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?
Answers
Answer:
100°
Explanation:
For a boiling point is it always 100°
Which types of matter are made of atoms
a. Mixtures
b. Elements
C. Compounds
D. All of the above
Answers
Answer:
D all above yes I think it's all above
Answer: D
Explanation: All of the above.
Plz mark brainliest:)
32 N of Force. 37 N force. How strong is the net force and in which direction?
Answers
Explanation:
They are working against each other. That means you subtract.
32 - 37 = -5
You are moving 5 units to the left because 37 is negative which means it is moving left. The key word is left. In physics, you would get the same answer if you did it this way.
37 - 32 = 5
The 5 moves in the same direction as the 37
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
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What is force and motion
Answers
Answer:
In physics, a force is any interaction that, when unopposed, will change the motion of an object. A force can cause an object with mass to change its velocity (which includes beginning moving from a state of rest), i.e., to accelerate. Force can also be described intuitively as a push or a pull.
lol
Two compounds of phosphorus and fluorine have the following
mass ratios.
Compound 1: 10.14 g fluorine for every 3.38 g phosphorus
Compound 2: 8.42 g fluorine for every 4.21 g phosphorus
Find the whole number ratio of masses of fluorine in compound
1 to compound 2.
Help me please
Answers
Answer: 3:2
Explanation: (10.14÷3.38)÷(8.42÷4.21)=1.5=3/2
What is the mass of an object with a density of 5.7 g/cm^3 and a volume of 48
cm^3? *
Answers
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.
To learn more about density, refer to the link below:
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Need help ASAP please
Answers
Answer:Melting can create steam, kind of like a nukeular plant exept no nukulear rods
2. Exothermic; decreases
3. Endothermic;increases
4. Exothermic; decreases
5. Endothermic; increases
How many carbon atoms are there in 2.23 grams of propane (C3H8)?
Answers
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.
Learn more about the number of particles/atoms here:
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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.
Answers
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:
Which of the following is the correct model of C7H16?
A.
B.
C.
D.
Answers
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
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
Answers
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: