Explanation:
frequency= velocity/ wavelength
= 340/1.36
=250
hormones that are essential for normal body growth and maturation include all the following except?
a. thyroid hormone
b. growth hormone
c. Ghrelin
d. insulin
why does a Costal area have less variation in temperature
Answer:
*The coastal areas experience less variation in temperature as compared to land. ... It means that water takes more time to get hot or cold then land. Therefore areas near sea or ocean have more moderate temperature in the day time and less cooler at night
Explanation:
How many of sodium (Na) are needed to make 4.5 liters of a 1.5mol/L of Na solution?
Answer:
Explanation:
First you will find the mole from the molarity and then the desired mass from the mole.
Bas +
PtF2 →
BaF2 +
Pts
Need to balance it
it is already balanced
REACTANTS
Barium sulfide (BaS) + platinum (Ii) fluoride
PRODUCT
Barium fluoride (BaF2) + Cooperite (PtS)
Hope this answer helps you dear! take care
Which of the following statements are true concerning product distribution in the halogenation of an alkane?
a. Halogenation of alkanes follows a chain mechanism.
b. The initiation process involves the formation of a halogen molecule.
c. Heat or UV light causes the weak halogen bond to break.
d. A radical is an intermediate with a single unpaired electron.
e. Halogenation of alkanes is a rearrangement reaction.
Halogens combine with alkanes to yield halogenoalkanes. It is a chain reaction.
Alkanes are a group of organic molecules whose functional group is the carbon - carbon single bond. The halogenation of alkanes refers to the process by which alkanes reacts with halogen molecules to yield halogenoalkanes.
The following are true statements regarding the halogenation of alkanes;
Halogenation of alkanes follows a chain mechanism.Heat or UV light causes the weak halogen bond to break.A radical is an intermediate with a single unpaired electron.Learn more: https://brainly.com/question/17638582
Question 1
Which of the following describes the movement of molecules in a solid?
O Molecules are stationary.
O Molecules vibrate in fixed positions.
O Molecules move fast enough to change position.
O Molecules move freely.
Please help ASAP!!!
Answer:
Molecules vibrate in a fixed position.
Explanation:
first one is just wrong.
third is liquid
fourth is gas
What element is a gas at room temp, has 6 valence electrons, and is non-reactive
Answer:
Noble gases
Explanation:
Noble gases are nonreactive, nonmetallic elements in group 18 of the periodic table. As you can see in the periodic table in the figure below, noble gases include helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), and radon (Rn).18 Jun 2021
how many nuetrons are in the nucleous of an atom number of 25?
Answer:
I believe there are 30
Explanation:
According to the electron configuration, which atom will be the most reactive?
1s^2 2s^2
1s^2 2s^2 2p^6 3s^2
1s^2 2s^2 2p^6 3s^2 3p^6
1s^2 2s^2 2p^6 3s^2 3p^6 4s^2
Answer:
The fourth atom.
Explanation:
Number of valence electrons in each of the four atoms:
First atom: two ([tex]2\, s^{2}[/tex].)Second atom: two ([tex]3\, s^{2}[/tex].)Third atom: eight ([tex]3\, s^{2}\; 3\, p^{6}[/tex].)Fourth atom: two ([tex]4\, s^{2}[/tex].)Without referring to a periodic table, the first, second, and fourth atoms would all belong to the alkali-earth metal elements. The third atom would belong to a noble gas element. (The four choices are beryllium, magnesium, argon, and calcium, respectively.)
Noble gas elements are highly stable. Thus, the third atom (argon) would be the least reactive among all four choices.
On the other hand, alkali-earth metals are reactive since they tend to lose their valence electrons. The reactivity of an alkali-earth atom depends on its ionization energy (the energy required to take a valence electron away from the atom.)
Since these atoms are in the same group, ionization energy would be smaller for atoms with a larger radius. In a given group, atoms with more filled electron shells would have a larger radius.
The first atom has two filled main shells, the second has three, whereas the fourth has four.
Thus, among the three alkali-earth metals in the choices:
[tex]\begin{aligned}&\text{Number of filled electron shells:} \\ & a < b < d\end{aligned}[/tex].
[tex]\begin{aligned}&\text{Atomic radius:} \\ & a < b < d\end{aligned}[/tex].
[tex]\begin{aligned}&\text{Ionization energy:} \\ & a > b > d\end{aligned}[/tex].
[tex]\begin{aligned}&\text{Reactivity:} \\ & a < b < d\end{aligned}[/tex].
The third choice (a noble gas) is the least reactive among the four choices:
[tex]\begin{aligned}&\text{Reactivity:} \\ & c < a < b < d\end{aligned}[/tex].
Overall, the fourth choice would be the most reactive among the four choices.
PLEASE ANWSER THIS!!
which is the best definition m of pitch?
A: pitch is how high or low a sound is
B: pitch is how loud a sound is
C: pitch is how well a sound travels through a medium
Answer:
A. because there both high pitched voice and low pitched ( girls have sweet, shrill ,high pitched good voice ) where as boys have horase ,low pitched medium voice )
PLS HELP THIS IS TO HARD PLS
9) Observe the halogens. Fluorine and chlorine are gases, bromine is a liquid, and
iodine is a solid all at room temperature.
Distinguish between these differences in phase.
A) From Fluorine to lodine, the number of electrons increases.
This allows the intermolecular forces to strengthen from
temporary dipole (dispersion) forces to permanent dipoles.
Therefore, iodine is a solid because it has the most electrons.
B) From Fluorine to lodine, the nucleus gets larger. More
neutrons, protons and electrons allow the atoms of these
elements to become more attracted to each other. This is also
the reason that the halogens are diatomic naturally.
) From Fluorine to lodine, the molecular mass increases. With
the increase in mass, there is an increase in protons. This causes
the strength of the intermolecular forces between particles to
increase as well.
D) From Fluorine to lodine, the molecular mass increases. The
electron polarizability increases with the mass increase. In turn,
this strengthens the temporary dipole (dispersion) forces
between particles
Iodine is much more easily polarizable than fluorine therefore temporary dipoles in the molecule are strengthened.
The halogens are members of group 17 in the periodic table. They are highly electronegative and seldom occur free in nature owing to their high level of reactivity.
We know that larger molecules are more easily polarized than smaller ones. Therefore, from Fluorine to lodine, the molecular mass increases. The electron polarizability increases with the mass increase. In turn, this strengthens the temporary dipole (dispersion) forces between particles. Hence the properties of halogens change smoothly down the group.
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If the following ions Mg2+, Cl-, Sr2+, OH- are placed in a test tube, the precipitate formed is
Answer:
I am so sorry if I am wrong but my guess is no precipitate is formed.
Explanation:
If the following ions[tex]Mg^{+2}[/tex],[tex]Cl^{-}[/tex], [tex]Sr^{+2}[/tex], [tex]OH^{-}[/tex] are placed in a test tube, the precipitate formed is [tex]Mg(OH)_{2}[/tex]
What is precipitation reaction?The chemical reaction in which white color insoluble substance formed in water is called precipitation reaction.The white solid substance accumulate at the surface or separate from the reaction is called precipitate.Why participate forms?When particular cation and particular anion in a aqueous solution combine to form an insoluble ionic solid. The reaction form precipitate or not is decide by solubility rules.To learn more precipitate about
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The anion O3− does not obey the octet rule. Draw its Lewis structure and state the type of octet-rule exception. Indicate the values of nonzero formal charges and include lone pair electrons.
One of the oxygen atoms in the anion O3− is hypervalent and the formal charge on this oxygen atom is -1.
Ozone is a triatomic molecule. The anion formed from ozone is called the ozonide anion. This anion is also triatomic. The resonance structures of the ozonide anion are shown in the image attached to this answer.
We can see that one of the oxygen atoms in the ozonide ion is hypervalent because it contains ten instead of eight electrons. This hypervalent oxygen atom has a formal charge of -1 while the two other oxygen atoms has a formal charge of zero.
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Potassium sulfate has a solubility of 15g/100g water at 40 Celsius. A solution is prepared by adding 39.0g of potassium sulfate to 225g water, carefully heating the solution, and cooling it to 40 Celsius. A homogeneous solution is obtained. Is this solution saturated, unsaturated, or supersaturated? The beaker is shaken and precipitation occurs. How many grams of potassium sulfate would you except to crystallize out?please help me to understant this
Answer:
5.25 grams of potassium sulfate will get crystallize out.
Explanation:
Solubility of potassium sulfate at 40 °C = 15 g/100 g
This means that at 40 °C 15 g of potassium sulfate will get completely dissolved in 100 of water.
39.0 g of potassium sulfate to 225 g water, carefully heating the solution.
Amount of potassium sulphate will get dissolve in 225 g of water at 40 °C will be:
[tex]\frac{15g}{100g}[/tex] × 225 = 33.75g
Amount of potassium sulfate precipitated out by the solution:
= 39.0 g-33.75 g = 5.25 g
At 40 °C 5.25 g of potassium sulfate will get precipitate out from the solution which means that solution is saturated.
Saturated solution are solution in which solute is dissolved in maximum amount. Further addition of solute results in precipitation of solute form the solution.
5.25 grams of potassium sulfate will get crystallize out.
(Hope this Helps can I pls have brainlist (crown)☺️)
Calculate the mass (in grams) of chlorine (Cl2) gas sample which occupies a 2.50 L container at a pressure of 1.22 atm and temperature of 27.8°C?
Answer:Nothing
Explanation:
The answer is nothing the tempatature isnt matched with the degrees this is false
Which solution has the same number of moles of KCl as 75.00 mL of 0.250 M solution of KCl?
25.0 mL of 0.175 M solution of KCl
129 mL of 0.145 M solution of KCl
20.0 mL of 0.200 M solution of KCl
50.0 mL of 0.125 M solution of KCl
100 mL of 0.0500 M solution of KCl
Answer:
None of them
Explanation:
The number of moles in 75ml is 0.01875moles while in 25ml is 0.004375 and in 129 ml is 0.018705.
REMEMBER: Molarity is the number of moles per litre so in order to get the number of moles you multiply the molarity of the substance by the quantity of the substance in litres.
129 mL of 0.145 M solution of KCl solution has the same number of moles of KCl as 75.00 mL of 0.250 M solution of KCl. Therefore, option B is correct.
What is molarity ?Molarity is defined as the number of moles of a solute in one liter of solution. A solution's molarity is also known as its molar concentration.
To calculate the molarity of a solution, divide the number of moles of solute by the total volume of solution in liters.
Molarity is a concentration unit that is defined as the number of moles of dissolved solute per liter of solution. Molarity is expressed as the number of millimoles per milliliter of solution when the number of moles and volume are divided by 1000.
Given:
number of mol = M ×V
= 0.250 M × 0.0750 L
= 1.87 × 10^-2 mol
volume, V = 1.29*10^2 mL
= 0.129 L
use:
number of mol,
n = Molarity × Volume
= 0.145 × 0.129
= 1.87 × 10^-2 mol
Thus, option B is correct.
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Mechanical waves travel fastest through
A -Solid
B -Liquid
C -Gas
D -Vacuum
Answer:
A-Solid
Explanation:
Waves travel faster in solids & slowest in gases
plz help me I will mark as brainlest
All three metals react with cold water.
Complete the word equation for these reactions.
metal + water ➡️ _______ + ________
Answer:
metal oxide +hydrogen gas
why do you continuously gain exactly the amount of mass you consume with each meal
Answer:
It depends on how much the calories and fat there is in the meals and if you don't get enough physical activity of the same amount of food that you eat it can lead to weight gain
Explanation:
đặc điểm cơ bản nào để phân biệt vật thể tự nhiên và vật thể nhân tạo
Answer:
natural materials like cotton
what is the name of something that starts with N and ends with G
Nutmeg
Nubbing
Notifying
Neezing
Nudging
Needing
Niffing
Narcotizing
Nanjing
Neighbouring
Nothing
Nimming
Neighboring
Netting
Nesting
Narcing
Nitpicking
Non-Living
Neutralizing
Nightwalking
Nonspeaking
When the pressure of a gas decreases, which quantity will increase, assuming all other variables are held constant?
OR
ОТ
On
OV
I don't think the answer is in one of the options- unless I am reading it wrong and there is a 'V' option.
The volume (V) of gas increases when the pressure of the gas decreases assuming all the other variables are held constant.
I hope this helps!
if 2.4l of chlorine at 400 mm hg are compressed to 725 mm hg at a constant temperature. what is the new volume?
Answer: 1.324L
Explanation: use Boyles law, sorry so late!
1.) Calculation: If 9.02 x 1024 particles of vinegar (HC2H3O2)HC2H3O2) are added to 16.5 moles of eggshell (CaCO3) and 6.35 moles g of
calcium acetate is formed. What is the;
(a) theoretical yield,
(b) actual yield and,
(c) percent yield
The theoretical yield of acetate is 2607 g. The actual yield of acetate is 1066.8 g. The percentage yield of acetate is 41%.
If 1 mole of vinegar contains 6.02 x 10^23 particles
x moles of vinegar contains 9.02 x 10^24 particles
x = 1 mole x 9.02 x 10^24 /6.02 x 10^23
x = 15 moles of vinegar
The reaction is as follows;
2HC2H3O2 + CaCO3 -----> Ca(C2H3O2)2 + H2O + CO2
Since 2 moles of vinegar reacts with 1 mole of carbonate
x moles of vinegar reacts with 16.5 moles of carbonate
x = 2 moles x 16.5 moles/ 1 mole
x = 33 moles of vinegar
We can see that the vinegar is the reactant in excess hence the carbonate is the limiting reactant.
Theoretical yield = 16.5 moles x 158 g/mol = 2607 g
Actual yield = 6.35 moles x 158 g/mol = 1066.8 g
Percent yield = 1066.8 g/2607 g × 100/1
= 41%
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Use the diagram below to answer 3 questions
Answer:
The element X is sulfur.
Sulfur will gain 2 electrons to become an ion.
The charge of sulfide ion is (2-).
Explanation:
Determine the concentration of a solution prepared by diluting 20.0 mL of a 0.200 M KCl to 250.0 mL.
Answer:
ok
Explanation:
What characteristics do dishwashing liquid, alcohol, vinegar, baking soda, and alcohol have in common?
Answer:
First, both ingredients are excellent at dissolving tough grime. However, vinegar alone will simply run off of most surfaces, while dish soap is too thick to use as a spray. But when you mix them together, you get an effective, sprayable cleaner that sticks to any surface!
A reaction between solid sodium hydroxide and gaseous carbon dioxide produced solid sodium carbonate and liquid water. Write out a balanced equation for this reaction.
Balanced:
2NaOH + CO2 → Na₂CO₃ + H₂O
Explanation:
To balance an equation, the amount of atoms on each side must be equal.
Atom Count on Reactant Side:
Na = 1O = 3H = 1C = 1Atom Count On Product Side:
Na = 2C = 1O = 4H = 2As you see, to simply balance the equation, put the 2 in order for the atom count on the reactant side to be equal to the product side. The 2 will add one more of each atom so that its the same as the product side.
Which statement best describes the effect of radioactive decay on a nucleus?
When radioactive decay occurs, the original nucleus splits into daughter nuclei and the resulting nucleus is more stable than the original nucleus. The nucleus can be of a different element than the original.
Unstable nuclei often undergo radioactive decay. In a radioactive decay, the unstable nucleus is broken up into other nuclei. Usually, the nuclei formed during radioactive decay are smaller in mass compared to the original nucleus.
Also, the resulting nucleus is more stable than the original nucleus. The nucleus can be of a different element than the original.
The effect is that the nucleus changes into the nucleus of one or more other elements. These daughter nuclei have a lower mass and are more stable (lower in energy) than the parent nucleus.