Answer:
A.326
Explanation:
B is incorrect because that would be 4 significant figures.
C is incorrect because that would be 5 significant figures.
D is incorrect because, while it is 3 significant figures, it is rounding the .6 down which doesn't make sense. since it's .6 you should be rounding up not down.
Consider an ion with the symbol X2+ formed from a representative element. (5.2, 5.3)a. What is the group number of the element?b. What is the electron-dot symbol of the element?c. If X is in Period 3, what is the element?d. What is the formula of the compound formed from X and the nitride ion?
Answer:
a) the element belongs to group 2
b) see image attached
c) Magnesium
d) X3N2
Explanation:
Any ion with the formula X^2+ was derived from group 2 elements. The group two element found in period 3 is magnesium alone.
Since the nitride ion has a valency of -3 and X^2+ has a valency of +2 , then a compound formed between X^2+ and the nitride ion will have the formula X3N2.
a. The group number of the element can be determined by knowing the charge of the ion. In the ion X2+ has a charge of 2+. Since representative elements typically form ions with charges equal to their group numbers, we can conclude that the group number of the element X is 2.
b. The electron-dot symbol, also known as Lewis dot symbol, represents the valence electrons of an element. Since X is a representative element in Group 2, it has two valence electrons.
c. If X is in Period 3, it could be one of the elements from Group 2 in that period. The most likely element would be Magnesium (Mg), as it is the representative element in Group 2 of Period 3.
d. The nitride ion has a charge of 3-. To form a neutral compound, the charges of X and the nitride ion must balance out. Since X has a charge of 2+ and the nitride ion has a charge of 3-, we need two X ions to balance the charge of three nitride ions. Therefore, the formula of the compound formed from X and the nitride ion is X3N2.
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A physical change is chemically the same after the experiment.
True
False
Answer: True
Explanation:
Reactants undergo chemical reaction to form products.this chemical equation represents one such reaction.the coefficient for one of the reactants or products is incorrect .which part of the chemical equation is incorrect
Answer:
Explanation:
The part of 10 O2 is wrong.
Explanation:
The correct equation can be written as follows:
2 C 4 H 10 + 13 O 2 → 8 C O 2 + 10 H 2 O
The equation was not balanced before.
For a balanced chemical reaction, the number of atoms before and after the reaction should be the same. This is because matter is neither created not destroyed in a reaction, It changes from one form to another through chemical reactions.
Select the correct statement about thermochemical equations from the following: Select one:
a. The specific heat capacity of all substances involved in the chemical reaction are listed to the right of the balanced chemical equation.
b. Because the enthalpy change of the reaction depends on the states of matter of the substances, they must be shown for each substance in the equation.
c. Positive values for the enthalpy change of a reaction indicate that the reaction released energy.
d. If the chemical reaction is reversed, then the arithmetic sign of the change in enthalpy stays the same.
Answer:
Because the enthalpy change of the reaction depends on the states of matter of the substances, they must be shown for each substance in the equation.
Explanation:
The enthalpy of a substance depends on the particular state of matter in which it occurs.
Therefore, in a thermo chemical equation, all the states of matters for all the chemical species in the equation must be accurately written so that the thermo chemical equation can be meaningful.
The correct statement about thermochemical equations is the enthalpy
change of the reaction depends on the states of matter of the substances,
they must be shown for each substance in the equation.
Enthalpy is defined as the heat change that occurs in a reaction or the sum
of the internal energy present. It is associated with change in matter and is
dependent on the physical states of the reactants and products.
This is the reason why the physical states such as solid, liquid, gas etc have
to be shown in a thermochemical equation.
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Compare and contrast how are predation and parasitism similar how do they differ
Read the scenario, then answer the questions. A 2 kg ball is thrown upward with a velocity of 15 m/s. What is the kinetic energy of the ball as it is being thrown? J What is the potential energy of the ball when it gets to its maximum height just before falling back to the ground? J
Answer:
225 for both answers
Explanation:
The only reason i know this is because i got it wrong. 225
Answer:
225J on both of the questions.
When sand is coated with a layer of trimethylhydroxysilane, (CH3)3SiOH, it repels water and can no longer get wet. Hydrophobic sand (aka, magic sand) is fun to play with, but it can also have useful applications in agriculture to reduce water consumption (Water Resour. Manag. 2010, 24, 2237–2246). Predict the geometry for the silicon atom in trimethylhydroxysilane.
The geometry of the silicon atom in trimethylhydroxysilane is:__________
Someone pls help me I don’t know this one
Calculate the millimoles of solute in 1.88 L of a 0.00713 M NaCN solution. millimoles:
Answer:
13.4 milimoles.
Explanation:
The following data were obtained from the question:
Volume = 1.88 L
Molarity = 0.00713 M
Millimoles of NaCN =?
Next, we shall determine the number of mole NaCN in the solution. This can be obtained as follow:
Molarity = mole /Volume
Volume = 1.88 L
Molarity = 0.00713 M
Mole of NaCN =?
Molarity = mole /Volume
0.00713 = moles of NaCN /1.88
Cross multiply
Mole of NaCN = 0.00713 × 1.88
Mole of NaCN = 0.0134 mole
Finally, we shall convert 0.0134 mole to Millimoles. This can be obtained as follow:
1 mole = 1000 millimoles
Therefore,
0.0134 mole = 0.0134 × 1000
0.0134 mole = 13.4 milimoles
Therefore, the millimoles of the solute, NaCN in the solution is 13.4 milimoles
List three different forms of potential energy
Answer:
Types of Potential Energy
Elastic Potential Energy. Anything that can act like a spring or a rubber band can have elastic potential energy. ...
Gravitational Potential Energy. There is a constant attractive force between the Earth and everything surrounding it, due to gravity. ...
Chemical Potential Energy.
(IF THIS HELPED CAN YOU GIVE ME A BRAINYLEST PLEASE?)
What is true about all uranium atoms?
They each have the same number of nuclear
particles.
They each have the same number of neutral
particles.
O They each have the same number of neutrons.
They each have the same number of protons.
Answer:
they each have the same number of protons
Answer:they each have the same number of protons
Explanation:
I just took the test
I need help on these two questions please!!!
Answer:
5. A. Shape and volume
6. A. Solid to liquid
7. C. Gas
It is possible to make a buffer that functions well near pH 7 using citric acid, which contains only carboxylate groups. Explain. Drag the terms on the left to the appropriate blanks on the right to complete the sentences.a. decreaseb. increasec. repulsionsd. associatese. attractionsf. dissociate1. Successive deprotonations______the (−) charge density on the resulting anion.2.This results in unfavorable electrostatic_____between the carboxylate anions, which reduces the likelihood that a proton would_____.3. It is more favorable for the proton to remain bound to reduce unfavorable charge_______.
Complete Question
it is possible to make a buffer that functions well near pH 7 using citric acid, which contains only carboxylate groups. Explain. Drag the terms on the left to the appropriate blanks on the right to complete the sentences.
Words : decrease, increase, repulsion, associates, attractions, dissociate
1. Successive deprotonations -------------- the (−) charge density on the resulting anion.
2.This results in unfavorable electrostatic --------- between the carboxylate anions, which reduces the likelihood that a proton would ----------
3.it is more favorable for the proton to remain bound to reduce unfavorable charge----------- . .
Answer:
1
Successive deprotonations increase the (−) charge density on the resulting anion.
2
This results in unfavorable electrostatic repulsion between the carboxylate anions, which reduces the likelihood that a proton would dissociate
3
It is more favorable for the proton to remain bound to reduce unfavorable charge repulsion
Explanation:
Generally
Successive deprotonations decrease the (−) charge density on the resulting anion.
This because deprotonations means removal of positive charge
This results in unfavorable electrostatic repulsion between the carboxylate anions, which reduces the likelihood that a proton would dissociate
It is more favorable for the proton to remain bound to reduce unfavorable charge repulsion
Two substances, A and B, with the same melting point. How can you determine if they are the same without using any form of spectroscopy? Explain in detail.
Answer:
Simply carry out the mixed melting point procedure
1 here grind the two substances mix them
2.take note of the melting point of the mixture this is P
3 also get the original product from a different source okay this is Q
4.so I the melting point of P = Q then they represent a similar compound
5. But if melting point of P is not equal to Q then one of the compounds is P is acting as an impurity so they are not the same
The compound has been similar or not has been determined with the determination of the shift in the melting point of the mixture of the two compounds.
The melting point can be defined as the temperature of the substance when it has been converted from the solid state to the liquid state.
The two substances were found to have the same melting point. The compounds have been determined whether they are similar or not by the determination of the melting point of the combined mixtures.
The compounds A and B have been mixed together, and the melting point has been determined. The similar compounds in mixing will give the same melting point. While if the compounds are different, there has been a shift in the melting point of the mixture.
Thus, the compound has been similar or not has been determined with the determination of the shift in the melting point of the mixture of the two compounds.
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Does standard enthalpy use net ionic equations?a. Trueb. False
Answer:
True
Explanation:
In an ionic reaction, the net ionic equation is used to calculate the standard enthalpy of reaction.
Hence the standard enthalpy of any ionic reaction can be obtained by considering its balanced net ionic reaction equation, hence the answer above.
Can somebody help me please? it’s urgent
Answers:
See attached table
Explanation:
The isotope symbol will have the mass number and chemical symbol. The atomic number will be equal to the number of protons because the atomic number is the number of protons in an atom. The electrons will be equal to the protons because the atom is neutral. The neutrons can be found by subtracting the number of protons from the mass number. The mass number can be found by adding the protons and neutrons. It is also in the name of the isotope.
What is kinetic energy? Give an example please.
Kinetic energy is moving energy or the energy of motion.
If an object is moving like a rock rolling down
a mountain, we say the rock has kinetic energy.
which can be found on the periodic table: elements, compoumds or mixtures? pleaae help!!!!!!!!
Answer:
Elements
Explanation:
A compound: contains atoms of different elements chemically combined together in a fixed ratio.
A mixture: contain different elements and compounds but the ratio is not fixed nor are they combined via chemical bonds.
Answer:
elements can be found on a periodic table
lab report for physical and chemical changes??!
Answer:
[See Below]
Explanation:
✦ Physical Changes:
✧ Is when the form changes, but not the chemicals in that form.
✧ An example of this would be chopping wood. It's still wood but it's a different size now. It's easier to burn it since it's smaller.
✦ Chemical Changes:
✧ Is when the chemicals inside that form change to something else entirely
✧ An example would be an egg, when you cook the egg it can turn into being scrambled or fried. But you can't eat the raw egg until the chemicals change.
~Hope this helps Mate. If you need anything feel free to message me.
Answer:
Here is an example of the full report for this type of lab. Includes data table etc. I would suggest making some changes on wording prior to submission
Explanation:
What’s the symbol of the element that has 8 protons, 9 neutrons, and 8 electrons
Answer:
oxygen
Explanation:
The given isotope has 8 protons and 8 electrons, so the atomic number of the given isotope is 8, which is the atomic number of oxygen.
Why enthalpy of combustion is always negative ?
Answer:
reason is Heat is involved, the reaction is exothermic and therefore heat is lost to the surrounding
Mike rides his motorcycle North at an average velocity of 20 meters/second for 500 seconds, how far did he ride?
Answer:
10000
Explanation:
Answer:10,000 meters
Explanation:20x500=10,000
Please answer ASAP >_<
What does xylem do in a plant?
•transport food
•transport water
•prevent water loss
•perform photosynthesis
Answer:
The correct answer is B. Transport water.
Explanation:
I did this quiz. :)
Xylem transport water. Therefore, the correct option is option B among all the given options. The vascular tissue of plants called xylem.
What is xylem?The vascular tissue of plants called xylem transports water plus dissolving minerals from the roots towards the rest of the plant while also offering structural support. The tracheary components, a collection of specialized, water-conducting cells, make up xylem tissue.
All vascular plants, along with the seedless club mosses, fern, horsetails, all angiosperms (flowering plants), and gymnosperms, include xylem in addition to phloem (tissue that transports glucose from the leaves to the rest of the plant) (plants with seeds unenclosed in an ovary). Xylem transport water.
Therefore, the correct option is option B.
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Which would be an adaptation for living in the tundra?
I Need Help Asap
Answer:
Long fur
Explanation:
Long fur is an adaption for the tundra because it is cold and snowy in the tundra, so therefore long fur is an adaption
Answer:
thic long fur that overs you
Explanation:
what is the mass number of an atom or ion with one proton, two neutrons, and one electron?
Answer:
3
Explanation:
mass no.=protons+neutrons
mass no.=1+2=3
Calculate the volume of a sample of mercury with a density of 14.6 g/mL and a mass of 1.00 g.
The answer is assumed to be in mL. Please include a numeric value only with significant figures
Answer:
hiiiiiiiijsiosoaplq
What volume of acetic acid of density 1.10g/cm3 is needed to react with 250 mL of 0.50M Stronuim hydroxide?
Answer:
[tex]V=13.6cm^3[/tex]
Explanation:
Hello,
In this case, given the reaction in which the acetic acid reacts with strontium hydroxide to yield water and strontium acetate:
[tex]2CH_3COOH+Sr(OH)_2\rightarrow Sr(CH_3COO)_2+2H_2O[/tex]
The first step here is to compute the moles of strontium hydroxide that are reacting given its volume in liters (0.250 L) and concentration:
[tex]n_{Sr(OH)_2}=0.50mol/L*0.250L=0.125molSr(OH)_2[/tex]
Next, considering the 1:2 mole ratio between the strontium hydroxide and the acetic acid (molar mass = 60 g/mol) we compute the grams of acid that are consumed:
[tex]m_{CH_3COOH}=0.125molSr(OH)_2*\frac{2molCH_3COOH}{1molSr(OH)_2} *\frac{60gCH_3COOH}{1molCH_3COOH}\\ \\m_{CH_3COOH}=15gCH_3COOH[/tex]
Then, by using the density of the acetic acid, we compute the volume:
[tex]V=\frac{m}{\rho}=\frac{15g}{1.10g/cm^3} \\ \\V=13.6cm^3[/tex]
Best regards.
Do molecules break or build from a solid to a liquid?
Answer:
they break
Explanation:
Molecules move more freely when it is a liquid state. To keep it a solid, it will bunch together.
Answer:
I think they break.
Explanation:
They do not build a solid to a liquid
Convert 75 mL of water to gallons (show work)
Answer:
0.01981 gallons.
Explanation:
In this problem, we need to convert 75 mL of water to gallons.
We know that, 1 gallon = 3785.41 mL
To convert 75 mL to gallons, we must use to the unitary method such that,
1 mL = (1/3785.41) gallon
So,
[tex]75\ mL=75\times \dfrac{1}{3785.41}\\\\=0.01981\ \text{gallons}[/tex]
So, there are 0.01981 gallons in 75 mL of water.
How is the light emitted by an atom related to its electron configuration?A. Light is produced when an electron moves from a higher to a lower energy level. The color of the light (as we see it) depends on the amount of energy emitted by the electron.B. Light is produced when an electron moves from a lower to a higher energy level. The color of the light (as we see it) depends on the amount of energy emitted by the electron.C. Light is produced when a proton moves from a higher to a lower energy level. The color of the light (as we see it) depends on the amount of energy emitted by the electron.D. Light is produced when a proton moves from a lower to a higher energy level. The color of the light (as we see it) depends on the amount of energy emitted by the electron.
Answer:
Light is produced when an electron moves from a higher to a lower energy level. The color of the light (as we see it) depends on the amount of energy emitted by the electron.
Explanation:
According to the Bohr's model of the atom, energy is given out by an atom when an electron moves from a higher to a lower energy level. The energy of the emitted light is equal to the energy difference between the two energy levels.
Hence ;
∆E= E2 - E1
Where;
E2 = energy of the higher energy level
E1 = energy of the lower energy level.
By supplying light of various frequencies and observing the frequency/wavelength of light emitted by a particular atom, its electron configuration can be determined.