Answer:
GRAPHENE is a single layer of graphite
Explanation:
each carbon atom bonded to 3 other carbon atoms forming a hexagonal lattice
5.The amount of pollution produced by cars was measured for cars using gasoline containing different amounts of lead. what is the independent, dependent and controlled variables?
Independent: Gasoline with different amounts of lead Dependent: Amount of pollution produced
Question 1 (2 points)
Which option can be classified as a pure substance?
Question 1 options:
heterogenous mixture
solution
homogenous mixture
compound
Question 2 (2 points)
Law of conservation of mass states that:
Question 2 options:
matter is destroyed
matter does not change
matter is neither created nor destroyed
matter is created
Question 3 (2 points)
What is a property of bases?
Question 3 options:
all of the above
Sour taste
Slippery touch
Ability to form hydronium ions+
Question 4 (2 points)
Which property do solutions with low pH values have?
What does it mean to have a neutral pH? - Aseptic Health
Question 4 options:
have a -OH group
feels slippery
turns litmus paper blue
tastes sour
Question 5 (2 points)
How do the products of chemical reactions compare to their reactants?
Question 5 options:
The products often have completely different properties than the reactants.
The products are usually more toxic than the reactants.
The products usuallyhave more mass than the reactants.
The products usually have more atoms than the reactants.
Question 6 (2 points)
Which of the following is an example of a physical change?
Question 6 options:
Water freezing into ice.
A piece of wood burning.
A toy car rusting.
Zinc producing hydrogen gas when mixed with water.
Question 7 (2 points)
What might happen if you mixed a strong acid with an equally strong base?
Question 7 options:
You would see an explosive chemical reaction.
The base would destroy the acid.
You'd wind up with a pH-neutral salt and water.
The acid would destroy the base.
Question 8 (2 points)
In the equation shown, what are the reactants?
2H2+O2àH2O
Question 8 options:
Hydrogen and oxygen molecules (2H2 and O2 )
Ice crystals
Hydrogen atoms (H)
Water molecules (H2O)
Question 9 (2 points)
Which phrase most accurately describes a chemical change?
Question 9 options:
A change in form
A change in taste
A change on the molecular level
A change in appearance
Question 10 (2 points)
What does it mean when there is a physical change?
Question 10 options:
A new substance has been formed.
Matter has changed from one substance into a new substance.
Matter has changed size, shape or form
Matter has changed on the molecular level.
help pls ill give 20 points!
Answer:
I didn't KNOW WHAT IS THE ANSWWR OF YOUR QUISTION IM SO SORRY
Explanation:
I WANT TO INTRODUCE SELF TO YOU CAN I
9. Which of Earth’s sphere consists of all living things? A. hydrosphere B. geosphere C. biosphere
Answer:
i think its b
Explanation:
i took it
Calculate the energy of a photon of light emitted from a hydrogen atom when an electron falls from level n
Answer: E
1
−
E
4
=
Δ
E
=
−
2.18
×
10
−
18
J
(
1
n
2
f
−
1
n
2
i
)
=
−
2.18
×
10
−
18
J
(
1
1
2
−
1
4
2
)
=
−
2.18
×
10
−
18
J
(
15
16
)
=
−
2.04
×
10
−
18
J
After you obtain the energy, then you can realize that that energy has to correspond exactly to the energy of the photon that came in:
|
Δ
E
|
=
E
photon
=
h
ν
=
h
c
λ
where
h
is Planck's constant,
c
is the speed of light, and
λ
is the wavelength of the incoming photon. Thus, the wavelength is:
⇒
λ
=
h
c
E
photon
=
(
6.626
×
10
−
34
J
⋅
s
)
(
2.998
×
10
8
m/s
)
2.04
×
10
−
18
J
=
9.720
×
10
−
8
m
=
97.20 nm
Explanation:
In Experiment 1, what volume did the propane gas occupy in the Erlenmeyer flask before the addition of any water?
This question is mentioning an experiment that is not being described about the volume of the propane gas in an Erlenmeyer before the addition of water.
In this case, since no information is given, it is possible to propose a suggested procedure of how to figure it out via gas laws, specifically, the ideal gas one, since no change is decribed before the addition of water:
[tex]PV=nRT[/tex]
Thus, you can solve for the volume, by dividing both sides by the pressure, so that you will get:
[tex]V=\frac{nRT}{P}[/tex]
Now, to ensure a correct calculation, make sure you have the moles (divide by the molar mass of propane, 44,1 g/mol, if you were given the grams), the temperature in K (add 273.15 if you have degree Celsius), the ideas gas constant as 0.08206 and the pressure in atm, in order to have consistent units.
If you need the volume in milliliters, you will need to multiply the previous answer by 1000 in order to perform the appropriate conversion.
Learn more:
https://brainly.com/question/15268548https://brainly.com/question/165210072- Bromo – 2 – methyl propane is :
(a) Primary alkyl halide
(b) Secondary alkyl Halide
(c) Tertiary alkyl amine
(d) Tertiary alkyl Halide
Answer:
(B) SECONDARY ALKYL HALIDE
How long does it take for eggs to get to room temperature
Takes 30 mins for the egg to reach room temperature
What is the change in oxidation number of bromine in the following re-dox reaction Cl 2 +2HBr 2HCl+Br 2 A -2;0 B) -1;0 C) 0: -1 D) 0;-2
Answer:
ANSWER
ANSWER: +1
EXPLANATION
What is the change in oxidation number of bromine in the following re-dox reaction Cl 2 +2HBr 2HCl+Br 2 A -2;0 B) -1;0 C) 0: -1 D) 0;-2
for Cl 2 +2HBr 2HCl+Br 2 , the Cl in Cl2 is reduced from "0" to
"-1" and the Br in HBr is oxidized from "-1" to "0"
So the change in oxidation number is +1
use the principles of atomic structure and/or chemical bonding to explain each of the following. in each part, your answers must include references to both substances. the atomic radius of li is larger than that of be. the second ionization energy of k is greater than the second ionization energy of ca. the carbon-to-carbon bond energy in c2h4 is greater than it is in c2h6. the boiling point of cl2 is lower than the boiling point of br2.
1. Atomic Radius:
Atomic radius increases down a group and decreases across a period. Lithium (Li) has a larger atomic radius than beryllium (Be) due to Li's additional electron shell. Be has fewer shells, resulting in a smaller radius.
2. 2nd Ionization:
Second ionization energy is the energy needed to remove a second electron. Potassium (K) has higher second ionization energy than calcium (Ca) due to K's electron configuration ([Ar] 4s¹), requiring breaking into a filled shell.
3. C-C Bond:
Carbon-to-carbon bond energy differs based on bond type. Ethene (C₂H₄) has a stronger double bond, requiring more energy to break, while ethane (C₂H₆) has a weaker single bond.
4. Boiling Point:
Boiling points relate to intermolecular forces. Chlorine (Cl₂) has lower boiling point due to weaker dispersion forces compared to bromine (Br₂), with stronger dispersion forces leading to higher boiling point.
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Why is it important that you not breathe on the baking soda test?
Baking soda is a salt of sodium and bicarbonate ions. In a soda test, the breath will raise the temperature as it contains water vapor and decomposes the soda.
What is the baking soda test?The baking soda is also called sodium bicarbonate, and the test uses sodium bicarbonate as a reactant. It is also a leavening agent that is used in the preparation of food.
Breath contains some amount of water vapor that alters the test by diluting it and resulting in the clouding of the test. The water vapor decomposes the baking soda and alters the test results.
Therefore, breath contains water vapor.
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the diagram of paper chromatography
I hope that the attachment helps you..
what viral components might serve as good targets for the design of antiviral chemicals?
If the average speed of a car is 45 km/hr, how far can it travel in 0.5 hours
Answer:
22.5 Km
Explanation:
45km/hr * 0.5 hr = 22.5km
what is the hybridization at each carbon atom in the molecule?
The carbon atoms are sp3 hybridized.
Hope this helps!
what do you put in the turkey cavity when not using stuffing
Which action reflects irresponsible lab safety behavior?
What do the electron configurations of the elements Mo and Pt have in common?
Answer:
All of the elements in a period have the same number of atomic orbitals. For example, every element in the top row (the first period) has one orbital for its electrons. All of the elements in the second row (the second period) have two orbitals for their electrons.
Explanation:
what scientist is credited with formulating the octet rule
Answer:
The electron configuration of the neon atom. American chemist Gilbert Lewis (1875-1946) used this observation to explain the types of ions and molecules that are formed by other elements. He called his explanation the octet rule.
Why are herbivores in level two of a food
web?
Worth 20 points :)
Answer:
Hey mate....
Explanation:
This is ur answer....
They tend to be small in size and there are many of them. The primary consumers are herbivores (vegetarians), Because of this inefficiency, there is only enough food for a few top level consumers, but there is lots of food for herbivores lower down on the food chain. There are fewer consumers than producers.
Hope it helps!
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hi. can you help me
A student group is involved in a restoration study of a nearby disturbed area. They decide to collect six soil samples and analyze them for carbon (C) and nitrogen (N). Two of the samples are found to be very high in C and N, but the other four samples are low in both. The students also notice that the color of the two soil samples that are high in C and N is very dark.
Requried:
What is the most likely explanation of the data?
The very dark soils samples that contain the highest amounts of carbon and nitrogen is loamy soil.
Soil is the outermost portion of the earth's crust on which plants grow. The appearance of a soil sample gives an idea of the type and nature of the soil it is.
We are told that two out of the six soil samples gathered are very dark and contains an enormous amount of carbon and nitrogen. These two must be samples of loamy soil.
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1. Which of these is an agent of chemical weathering?
copper patina
iron oxide
acid rain
iron
Answer:
Test answers
1. Water carving out a limestone cave
2. Oxidation
3. Acid rain
(Got 100%)
Explanation:
The primary agents of chemical weathering are water, oxygen and acids. So acid rain is an agent of chemical weathering. Option C is correct.
Which are the agents of chemical weathering ?Water, and many chemical compounds found in water, is the main agent of chemical weathering. One of the most abundant rock-forming minerals, chemically reacts with water and water-soluble compounds to form clay.
Water contains many weak acids such as carbonic acid. The primary agents of chemical weathering are water, oxygen and acids.
These react with surface rocks to form new minerals that are stable in, or in equilibrium with, the physical and chemical conditions present at the earth's surface.
Hence, option C is correct.
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what is the strongest type of intermolecular forces present between a stearic acid molecule and a water molecule?
The bond and the force present between molecules is called intermolecular force. A hydrogen bond is present between the stearic acid and a water molecule.
What are hydrogen bonds?Hydrogen bonds are the intermolecular force that forms a dipole-dipole interaction with an electronegative atom in the presence of the lone pair of electrons.
In stearic acid, [tex]\rm C_{18}H_{36}O_{2}[/tex], hydrogen bonding exists between the oxygen and the hydrogen atom of the molecule.
Therefore, a hydrogen bond is present between stearic acid and the water molecule.
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What makes a balloon electrically charged?
A. Adding more air to the balloon
B. Placing the balloon against a wall
C. Rubbing the balloon against your hair
D. Running water over the balloon
Answer:
C
Explanation:
running the balloon against your hair
please help quickly i will give 15 points
what do you do if you add a bit too much solvent when filling the volumetric flask to the mark
If excess solvent is added, discard the entire solution and begin the process of preparing the solution afresh.
It is common to prepare solutions using a standard volumetric flask. In this method, the required amount of solid or liquid is added to the volumetric flask and made up to mark with solvent.
Sometimes, it is possible to mistakenly exceed the mark as the solvent is added. In such cases, you must discard the entire solution and begin the process of preparing the solution afresh.
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A chemist heats a fixed amount of gas in a sealed glass container. Which law is the chemist most likely
investigating? (1 point)
O Charles's law, by seeing how changes in temperature affect the volume of the gas
O Charles's law, by seeing how changes in temperature affect the pressure of the gas
O Gay-Lussac's law, by seeing how changes in temperature affect the volume of the gas
O Gay-Lussac's law, by seeing how changes in temperature affect the pressure of the gas
The chemist is most likely investigating Gay Lussac's law. To study the changes in temperature affect the pressure of the gas when a fixed amount of gas is heated in a sealed glass container. Therefore, option (D) is correct.
What is Gay Lussac's law?Gay-Lussac's law states that when the volume of the gas is kept constant the pressure of a gas is directly proportional to the absolute temperature.
The mathematical expression of Gay Lussca's law can be written as follows:
P/T = k
It can be also represented as the pressure being directly proportional to the temperature of the gas.
P ∝ T (where V volume of gas is constant)
or
[tex]\frac{P_1}{T_1} =\frac{P_2}{T_2}[/tex]
Where P₁ and T₁ are the initial temperature and pressure of the gas. The P₂ and T₂ are the final temperature and pressure of the gas.
As the container is sealed on heating the volume of the gas will not change. On increasing the temperature the molecules of the gas acquire more and more kinetic energy. So the pressure of the gas will increase.
Therefore, the chemist is investing the Gay-Lussac's law by noticing how changes in temperature affect the pressure of the gas.
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Will any of these properties change after a couple of hours in the sun
Explanation:
what properties are you talking about?
A doctor who specializes in treating diseases of nervous system
neurologist
nephrologist
ophthalmologist
cardiologist
Hurry i only have till today to finsh this!
Instructions: For this lab, use the Energy Skate Park Basics simulation and the lab report to record your information. You will submit your completed lab report.
Answer:
With the friction on, the minimum height I can place the skater so that he makes it all the way around the loop is 6 meters. This is about a meter higher than if the friction were turned off. The “lost” energy is going towards thermal energy. This means in real life that heat is being created due to the friction.
Explanation:
Answer:
With the friction on, the minimum height I can place the skater so that he makes it all the way around the loop is 6 meters. This is about a meter higher than if the friction were turned off. The “lost” energy is going towards thermal energy. This means in real life that heat is being created due to the friction.
Explanation: