Answer:
False
Explanation:
hi! sodium has one valence electron while magnesium has 2. this is because of their position on the periodic table. sodium is the first in the row, meaning it has one valence electron. magnesium is next to sodium on the periodic table, meaning it is second in the row and has two valence electrons. hope this helps!
is change in color a physical change
Answer: A change in color is not always a chemical change. If one were to change the color of a substance in a non-chemical reaction scenario, such as painting a car, the change is physical and not chemical.
Solid → Liquid: Melting
Solid → Gas: Sublimation
Liquid → Gas: Vaporization
Gas → Liquid: Condensation
Explanation:
Complete the given equation and mention whether heat is absorbed or evolved during the chemical reaction.
NaOH + HCl ……………. + …………….
need help !! :)
no unwanted ans ...
Answer:
NaCI + H2O
this is answer
A small container of perfume is opened in a classroom. Soon every student in the room smells the perfume. Explain this in terms of molecules.
Answer: possibly diffusion
Explanation:
all particles are in motion unless at a certain degree so they'd spread throughout the room diluting as they continue to spread out.
Which chemical reaction occurs between steps 1 and 5?
Find the percent composition of OXYGEN in Manganese (III) nitrate, Mn(NO3)3.
Answer:
Mn(NO3)3 Molar mass = (54.93) + (3 x 14) + (9 x 16) = 240.93g/mol
Total number of Oxygen atoms in formula = 9
Total mass of oxygen atoms theoretically in the formula = 9x16 = 144g/mol
Oxygen's percentage composition:
(144/240.93) x 100 = 59.7% of the compound is oxygen
The energy required to cause a gaseous atom or ion to release a electron is what?
Answer:
The ionization energyExplanation:
The ionization energy is required to cause a gaseous atom or ion to release a electron.
Almost 99% of the Earth's atmosphere is made up of two gases. What ere the two gases and the percents of each?
Answer:
21% oxygen and 78%nitrogen
Explanation:
Answer:
Nitrogen and Oxygen
Explanation:
nitrogen - 78 %
oxygen - 21%
If a sample of air in a school container was heated, would the percentage of oxygen in the air increase, decrease, or remain unchanged?
Answer:
increase
Explanation:
Let's suppose we have a sample of air in a closed container. We heat the container and we want to predict what would happen to the pressure.
According to Gay-Lussac's law, the pressure of a gas is directly proportional to its absolute temperature.
Thus, if we increased the temperature of the air by heating it, its pressure would increase.
If a sample of air in a closed container was heated, the total pressure of the air would increase.
an ideal gas is allowed to expand from 3.20L to 27.2L at constant temperature. By what factor does the volume increases
Answer:
Explanation:
This is just a ratio question. Factor of increase = 27.2 / 3.20 = 8.50
Nitrogen and oxygen can be separated from liquid air.State the name of this process.
Explanation:
Because of the earth and climate change the point of incidence mean that you mean by engineers to social evils activities.
What is the Lewis structure for Iodide?
Answer:
In the Lewis structure for IF5 you'll need to put a total of 12 valence electrons on the Iodine atom in order to draw the Lewis structure. Remember that Iodine (I) can hold more than eight valence electrons. For the IF5 Lewis structure, calculate the total number of valence electrons for the IF5 molecule
Explanation:
I be knowing hope this helps
the wind pushes a paper cup along the sand at a beach. the cup has a mass of 0.025 kg and accelerates at a rate of 5 m/s2. how much force is the wind exerting on the cup
To find the force,
⇒ must know the force's formula ⇒ F = MA
M: mass of the objectA: acceleration of the objectLet's consider the information given:
cup has a mass of 0.025kg --> 'M'accelerates at a rate of 5 m/s^2 --> 'A'Let's solve:
[tex]F=MA=0.025kg*5m/s^2=0.125N[/tex]
Thus the force is 0.125N
Answer: 0.125N
Hope that helps!
The web site of the Nobel Prize explains that readers who want to inspect the Curies' notebooks must sign a paper
that states that they are aware of the health risks that are involved with handling the notebooks. What health risk is
most likely to occur from handling the notebooks?
O excessive coughing
o anemia
O muscle cramping
O swelling of the joints
Answer: anemia because Marie curie died of anemia
Given that the molar mass of NaCl is 58. 44 g/mol, what is the molarity of a solution that contains 87. 75 g of NaCl in 500. ML of solution? Use Molarity equals StartFraction moles of solute over liters of solution EndFraction. 0. 333 M 0. 751 M 1. 50 M 3. 00 M.
Answer:
D
Explanation:
Given that the molar mass of NaCl is 58.44 g/mol, we want to determine the molarity of a solution that contains 87.75 g of NaCl in 500. mL of solution.
Recall that molarity is given by:
[tex]\displaystyle \text{M} = \frac{\text{ mols solute}}{\text{ liters soln.}}[/tex]
Therefore, we can convert the amount of NaCl in the solution to moles of NaCl and the volume from milliliters to liters:
[tex]\displaystyle \begin{aligned} \text{M} & = \frac{(87.75 \text{ g NaCl})}{(500. \text{ mL soln.})} \cdot \frac{1 \text{ mol NaCl}}{58.44 \text{ g NaCl}} \cdot \frac{1000 \text{ mL soln.}}{1 \text{ L soln.}} \\ \\ & = 3.00\text{ } \frac{\text{mol NaCl}}{\text{ L soln.}} \\ \\ & = 3.00 \text{ M} \end{aligned}[/tex]
Hence, our answer is D.
look at the picture
Answer:
The strong electric force.
Explanation:
Trust me. If its wrong, comment on this, don't delete it. If someone else answers with the wrong question than other students might get the answer wrong. So if its right, say that it is, if its wrong, tell others what the real answer is.
what is the number of the atom in 1 mole of methanol CHɜOH ?
Exhaling CO2 (Carbon Dioxide) is an example of what?
A-Excretion
B-movement
C- Nutrition
D- Reproduction
How many moles of water is 5.02x1018 molecules
of water?
Answer:8.334×10^-6 moles
Explanation:
a mole is 6.023×10^23
5.02×10^18 ÷ 6.023×10^23=8.33×10^-6
factors that affect the rate of a chemical reaction include which of the following? i. frequency of collisions of reactant particles ii. kinetic energy of collisions of reactant particles iii. orientation of reactant particles during collisions
To solve such this we must know the concept of double displacement reaction. Therefore, the correct option is option B that is kinetic energy of collisions of reactant particles.
What is chemical reaction?Chemical reaction is a process in which two or more than two molecules collide in right orientation and energy to form a new chemical compound. The mass of the overall reaction should be conserved. There are so many types of chemical reaction reaction like combination reaction, double displacement reaction.
There are so many factors that affects the rate of reaction, among these, kinetic energy of collisions of reactant particles affect the rate of a chemical reaction. the rate of reaction is directly proportional to the rate of chemical reaction.
Therefore, the correct option is option B.
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Could someone help me with this?
Solving part-1 only
#1
KMnO_4
Transition metal is Manganese (Mn)#2
Actually it's the oxidation number of Mn
Let's find how?
[tex]\\ \tt\Rrightarrow x+1+4(-2)=0[/tex]
[tex]\\ \tt\Rrightarrow x+1-8=0[/tex]
[tex]\\ \tt\Rrightarrow x-7=0[/tex]
[tex]\\ \tt\Rrightarrow x=+7[/tex]
x is the oxidation number#3
Purple as per the color of potassium permanganate#4
[tex]\boxed{\begin{array}{c|c|c}\boxed{\bf Tube} &\boxed{\bf Charge} &\boxed{\bf No\:of\; electrons\: loss}\\ \sf 2 &\sf +6 &\sf 6e^-\\ \sf 3& \sf +2 &\sf 2e- \\ \sf 4 &\sf 4 &\sf 4e^-\end{array}}[/tex]
which statement describes how the binary ionic compound cacl2 is named?
A wave with a smaller wavelength has _______ energy than one with a larger wavelength.
A wave with a smaller wavelength has UV radiation energy than one with a larger wavelength.
Additional information :- It is harmful rays as a continuous effect on humans can cause skin and eye disorders. ... A large amount of UV rays comes from the sun is absorbed by the ozone layer in the atmosphere. Some other sources of UV rays are black lights, mercury lamps, and tanning lights.Uses of UV Rays
The UV light is found in nature from sunlight and the application of sunlight is present in every field. It is present in both commercial and industrial purposes. Generally, it is used in purifying air, water treatment, skin treatment, indoor gardening, things identifying, and more uses by UV lamps.The UV rays are used in a wide range, ranging from medical therapy to photography.▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬
which are the only two elements liquid at room temperature?
Answer:
mercury and bromine are the only two elements
An electron is present at an energy level with an energy of 16.32 x 10−19 J. During a transition to another level, 5.4 x 10−19 J of energy was absorbed. Which of the following is true about the present state of the electron?
Answer Choices:
A. The electron moved down to an energy level and has an energy of 10.92 x 10−19 J.
B. The electron moved down to an energy level and has an energy of 21.72 x 10−19 J.
C. The electron moved up to an energy level and has an energy of 10.92 x 10−19 J.
D. The electron moved up to an energy level and has an energy of 21.72 x 10−19 J.
Answer:
D. The electron moved up to an energy level and has an energy of 21.72 x 10−19 J.
The statement which is true about electrons is that the electron moved up to an energy level and has an energy of 10.92 x 10[tex]^-[/tex]¹⁹ J which is found out as 16.32 x 10[tex]^-[/tex]¹⁹ -5.4 x 10[tex]^-[/tex]¹⁹=10.92 x 10[tex]^-[/tex]¹⁹ J.
What is an energy level?Electrons present in an atom revolve in different orbits which are stationary states and are also called as energy levels. The energy levels are numbered as integers which are also called as principal quantum numbers.
Energy of the stationary state is given as E= -R
1/n² where R
is the Rydberg's constant. When an electron is excited, and it moves from lower to higher energy levels there is absorption of energy, while when it moves from higher energy level to lower energy level it radiates or gives out energy in the form of radiation.
They can also be defined as the distances between electron and nucleus of an atom . Electrons present in K energy level have least energy .Energy level diagrams are studied to understand nature of bonding , placement of electrons in orbits and and elemental behavior under certain conditions.
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(1) What is the history of renewable energy in the United States?
(2)What are the advantages and
disadvantages of renewable energy?
(3)What can you do to help forsee a sustainable energy future
in the United States?
You must address all of these
questions in a minimum 2 paragraphs.
Answer:
Historically, wood was the main source of U.S. energy until the mid-1800s and was the only commercial-scale renewable source of energy in the United States until the first hydropower plants began producing electricity in the 1880s.
The Advantages of Renewable Energy Resources-A Fuel Supply That Never Runs Out.Zero Carbon Emissions.Cleaner Air and Water.Disadvantages of Renewable Energy-he Electricity Generation Capacity is Still Not Large Enough.Renewable Energy Can be Unreliable.
First, we need to take advantage of the world's abundant natural gas resources and reduce coal consumption;
Second, governments must support development of carbon capture and storage technology to make fossil fuel use cleaner;
Explanation:
Look at the diagram of metallic bonding. The light blue area represents a sea of... what?
Answer:
try elcetrons
Explanation:
if not then i'm sorry
The light blue area represents electrons.
What is an electron?
An electron is a negatively charged subatomic particle. It can be either free (not attached to any atom) or bound to the nucleus of an atom. Electrons in atoms exist in spherical shells of various radii, representing energy levels. The larger the spherical shell, the higher the energy contained in the electron.
What is the role of electrons?
Electrons play an essential role in numerous physical phenomena, such as electricity, magnetism, chemistry and thermal conductivity, and they also participate in gravitational, electromagnetic and weak interactions.
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How many grams of LiF would need to be dissolved to make 400 mL of a 1.67 M solution?
Group of answer choices
30 g LiF
20 g LiF
10 g LiF
40 g LiF
Answer:
20g
Explanation:
hope helpful.............
what can scientists gain clues about by analyzing the speed at which seismic waves travel?
why don't elements in a group have consicutive atomic numbers?
Answer:
Periods have consecutive atomic number as they are in a row and groups are vertical meaning they are in a column and groups have similar properties
Summarize: Complete the following statements:
A. 1 mole of any element contains 6.0221 x 1023 _____
B. 1 mole of any compound contains 6.0221 x 1023 ______
Answer:
Explanation:
Taking into account the definition of Avogadro's Number, the correct answers are:
1 mole of any element contains 6.023×10²³ atoms
1 mole of any compound contains 6.023×10²³ molecules
You have to know that Avogadro's Number or Avogadro's Constant is called the number of particles that make up a substance (usually atoms or molecules) and that can be found in the amount of one mole of said substance. Its value is 6.023×10²³ particles per mole.
Avogadro's number represents a quantity without an associated physical dimension, so it is considered a pure number that allows describing a physical characteristic without an explicit dimension or unit of expression.
Avogadro's number applies to any substance, because the number of elementary units in a mole of a substance is, by definition, a constant that does not depend on the material or the type of particle considered.
So, in this case, the correct answers are:
1 mole of any element contains 6.023×10²³ atoms
1 mole of any compound contains 6.023×10²³ molecules
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