There are 1.16x10²² sulfide ions (S²⁻) in 15 dg of sodium sulfide (Na₂S).
The equation for sodium sulfide is the following:
Na₂S → 2Na⁺ + S²⁻ (1)
So from equation (1), we can see that in 1 mol of sodium sulfide we have 1 mol of sulfide ions and 2 moles of sodium ions.
First, let's find the number of moles of Na₂S
[tex] n_{Na_{2}S} = \frac{m_{Na_{2}S}}{M_{Na_{2}S}} [/tex] (2)
Where:
[tex]m_{Na_{2}S}[/tex]: is the mass of Na₂S = 15 dg = 1.5 g
[tex]M_{Na_{2}S}[/tex]: is the molar mass of Na₂S = 78.0452 g/mol
The number of moles of Na₂S is (eq 2):
[tex] n_{Na_{2}S} = \frac{1.5 g}{78.0452 g/mol} = 0.0192 \:mol [/tex]
We can find the number of ions of S²⁻ with Avogadro's number, knowing that the number of moles of Na₂S is equal to the number of moles of S²⁻ (eq 1).
[tex] ions_{S^{2-}} = \frac{6.022 \cdot 10^{23} \:ions}{1\:mol}*0.0192 \:mol = 1.16 \cdot 10^{22} \:ions [/tex]
Therefore, there are 1.16x10²² sulfide ions in 15 dg of sodium sulfide.
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Bryan and Alyssa are playing tug-of-war against Daniel and Maria. Bryan and Alyssa are exerting a combined force of 10 N. Daniel and Maria are exerting 12 N of force.
Which of the following has resulted?
A.
a balanced force moving everyone in Daniel and Maria's direction
B.
a balanced force leaving everyone in the same place
C.
an unbalanced force moving everyone in Daniel and Maria's direction
D.
an unbalanced force moving everyone in Bryan and Alyssa's direction
The correct answer is Option (C) An unbalanced force moving everyone in Daniel and Maria's direction.
What is balanced force?The force which is opposite in direction and equal in size.A man pushing a wall is example of balanced force.What is unbalanced force?The force which changes the speed , position and direction of the object to which it is applied is known as unbalanced force ,Turning a cartwheel is an example of unbalanced force.
Why Other options are incorrect? Bryan and Alyssa are exerting a combined force of 10 N.Daniel and Maria are exerting 12 N of forceAs , a result the force applied by the Daniel and Maria is greater then the force applied by Bryan and Alyssa So the direction of Bryan and Alyssa changes.Hence , an unbalanced force moving everyone in Daniel and Maria's direction
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Which of the following animals is not a first-order prairie consumer? help fast
hawk
gopher
deer
squirrel
Answer:
The answer would be the hawk.
Explanation:
First-order consumers directly depends on grass or plants for survival.
A hawk gets its food from eating animals.
Again, hope this helps :D
21. When considering the Bohr model of a neon atom, which of the following is a true statement?
Ten protons would be located in the nucleus, and 10 neutrons would be on the outside of the atom orbiting in rings.
Ten protons would be located in the nucleus, and 10 electrons would be on the outside of the atom orbiting in rings.
O Ten protons would be located in the nucleus, and 20 neutrons would be on the outside of the atom orbiting in rings.
OTwenty protons would be located in the nucleus, and 10 electrons would be on the outside of the atom orbiting in rings.
The characteristics of the Bohr model allow you to find that the correct answer for the distribution of particles in the atom is:
b) Ten protons would be located in the nucleus, and 10 electrons would be on the outside of the atom orbiting in rings.
The bohr model was initially developed for hydrogen, where it manages to fully explain the spectrum of the hydrogen atom, it was quickly spread to other multi-electronic atoms with the characteristic of having a single electron in their last orbit.
The extension to atoms with more than one electron in the last shell the model results are not completely correct.
The Bohr model uses Rutherford's knowledge that the atomic nucleus is a very small part of an atom that contains all its mass, that is, it contains the protons and neutrons and the electrons are in circular orbits around the nucleus.
In the case presented of Neon, its electronic configuration is
1s² 2s² 2p⁶
Let's examine the different claims:
a) False. Protons and neutrons form the mass of the atom, therefore they are both in the nucleus.
b) True. The protons are in the nucleus and the electrons are in circular orbits.
c) False. All protons and neutrons must be in the nucleus, plus neon only has 10 neutrons.
c) False. The number of protons determines the type of atom. An atom with twenty protons is Calcium atom .
In conclusion, using the characteristics of the Bohr model we can find that the correct answer for the distribution of particles in the atom is:
b) Ten protons would be located in the nucleus, and 10 electrons would be on the outside of the atom orbiting in rings.
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Sharon reads two different articles about avocados. The first article, in a weight-loss magazine, claims that avocados are unhealthy because they are high in fat. The second article, in an annual publication from a doctors’ group, claims that the fat in avocados is a type that is good for the heart.
To assess these claims, which question might Sharon ask?
Which source do avocados come from?
Where are avocados sold?
Is the source an authority on the subject?
How much do avocados cost?
Answer:
The correct anwser would be C
Explanation:
Answer:
The answer is C. Is the source an authority on the subject?
Explanation:
Which of the following are properties of compounds formed by covalent bonding (Select all that apply)
1. When you dissolve an covalent compound in water, the solution does not conduct electricity.
2. Covalent compounds often have lower melting points than ionic compounds.
3. When you dissolve an covalent compound in water, the solution conducts electricity.
4. Covalent compounds form when combining two or more nonmetal atoms.
5. Covalent compounds form when combining a two metal atoms.
6. Covalent compounds form when combining a metal atom with a nonmetal atom.
Answer:1, 2, and 4
Explanation:
covalent bonds are not ionic. the elements SHARE electrons
Which of the following are properties of compounds formed by covalent bonding (Select all that apply)
1. When you dissolve an covalent compound in water, the solution does not conduct electricity.
2. Covalent compounds often have lower melting points than ionic compounds.
3. When you dissolve an covalent compound in water, the solution conducts electricity.
4. Covalent compounds form when combining two or more nonmetal atoms.
5. Covalent compounds form when combining a two metal atoms.
6. Covalent compounds form when combining a metal atom with a nonmetal atom.
The properties of covalent compounds are option 2, 3 and 4. Covalent bonds are weaker than ionic bonds.
What are covalent bonds?Covalent bonds are formed by sharing electrons between two atoms. Non metals with comparable electronegativities forms covalent bonds. They are weaker than ionic bond. Thus have lower melting point.
Melting point depends on the bond strength that's why covalent compounds have lower melting point compared with ionic bonds.
Polar covalent bonds can conduct electricity when dissolved in water because of the presence of free electrons. Thus option 3 is correct.
Hence, the properties in option 2, 3 and 4 are correct for covalent compounds.
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In general the state of matter with the most energy is ?
Gas
Gas particles got the most energy because of how freely the molecules move
Hope this helped you, have a good day bro cya)
WHAT IS THE MIXTURE OF BOILING POINT AND MELTING POINT?
(ive been stuck on that question for AGES)
Answer:
A pure substance has a sharp melting point (melts at one temperature) and a sharp boiling point (boils at one temperature). A mixture melts over a range of temperatures and boils over a range of temperatures. Homogeneous mixtures are called solutions.
Answer:
What is it has fixed boiling point substance or mixture? A pure substance has a sharp melting point (melts at one temperature) and a sharp boiling point (boils at one temperature). A mixture melts over a range of temperatures and boils over a range of temperatures. Homogeneous mixtures are called solutions.
Explanation:
lol they got it from go ogle
Physical properties are
Answer:
the 1st one
Explanation:
sodium atom cannot exist freely In nature but argon atom can.give reason
Answer:
argan can exist freely in nature because it has stable configuration whereas sodium atom cannot exist freely nature because do not have stable configuration.
Explanation:
brainiest!!!!!
Because that's the correct answer
how is an inoculating loop or needle sterilized prior to use?
Answer:
it is placed over a bunsen burner to heat up and remove all bacteria
Explanation:
Which unit could be used to measure volume?
Need help
Answer:
A
Explanation:
Because it milliliter and litre is used to measure volume not meter or millimeter
PLEASE HELP!!!!!!! (in a few minutes please)
B
Hope this helped you, have a good day bro cya)
Answer: Although metamorphic rocks typically form deep in the planet's crust, they are often exposed on the surface of the Earth.
Explanation:
Trường hợp nào sau đây là chất tinh khiết
how many electrons can occupy a filled 3rd energy level
Answer:
The third energy level can actually hold up to 18 electronsi will give u brainiest if u help me
How can a charged balloon attract a wall without any contact?
The positive charges of the uncharged wall move to the outside.
The wall changes shape and the positive charges move to the inside.
The negatively charged balloon repels and moves away from the wall.
A positive charge in the balloon attracts the negative charges in the wall
Answer:
A positive charge in the balloon attracts the negative charges in the wall
Explanation:
The question states attract, so we know it's not going to be option C.
The wall clearly doesn't change shape, so that eliminates option B as well.
The balloon gets positively charged, and so for an attractive force to appear, you need the opposite charge from the wall, i.e. negative.
Remember: opposite charges attract
Which means, the only option that makes sense is Option D.
P.S.: You could've concluded it's option D just because it's the only one that contains the word "attract" in there!
Hope I helped! :)
Answer:
a positive charge in the ballon attract the negative charge of the wall
Explanation:
calculate the mass required to prepare 2.5 L of 1.0 M NaOH solution. Given that the molar mass for NaOH is 40 g/mol.
Answer:
The required mass to prepare 2.5 L of 1.0 M NaOH solution is 100 g
Explanation:
We do this by preparing the equation:
Mass = concentration (mol/L) x volume (L) x Molar mass
Mass = 1.0 M x 2.5 L x 40 g/mol
Mass = 100 g
Answer:
[tex]100\; \rm g[/tex] of [tex]{\rm NaOH}\; (s)[/tex] would be required.
Explanation:
The quantity of solute in a solution of concentration [tex]c[/tex] and volume [tex]V[/tex] would be [tex]n = c \cdot V[/tex].
It is given that volume [tex]V = 2.5\; \rm L[/tex] for the solution in this question. It is also given that the concentration of the [tex]\rm NaOH[/tex] solute in this solution is [tex]c = 1.0\; \rm M[/tex], which is the equivalent to [tex]c = 1.0\; \rm mol \cdot L^{-1}[/tex].
Apply the equation [tex]n = c \cdot V[/tex] to find the quantity of [tex]\rm NaOH[/tex] in this solution:
[tex]\begin{aligned}n &= c \cdot V \\ &= 1.0\; \rm mol \cdot L^{-1} \times 2.5\; \rm L \\ &= 2.5\; \rm mol\end{aligned}[/tex].
Multiply the quantity [tex]n[/tex] of [tex]\rm NaOH[/tex] in this solution with the formula mass [tex]M[/tex] of [tex]{\rm NaOH}\![/tex] to find the corresponding mass:
[tex]\begin{aligned}m &= n \cdot M \\ &= 2.5\; \rm mol \times 40\; \rm g \cdot mol^{-1} \\ &= 100\; \rm g\end{aligned}[/tex].
Thus, this solution would contain [tex]100\; \rm g[/tex] of [tex]{\rm NaOH}[/tex].
It would thus take [tex]100\; \rm g[/tex] of [tex]{\rm NaOH}[/tex] to prepare this solution.
Define what the goldilocks zone in our solar system ?
Answer:
the "goldilocks zone" is the habitable zone around a star where it's not too hot and not too cold, so liquid water and life can exist on the planets in this zone.
Explanation:
The distance Earth orbits the Sun is just right for water to remain a liquid and for life to not be frozen or fried. This distance from the Sun is called the habitable zone, or the Goldilocks zone.
what is formed when the number of electrons is changed?
Answer:
Explanation:
Whether the electrons are added or given away makes no difference to the name given to parent atom -- It is called an ion which means that it has a charge. The word atom is reserved for something on the periodic table that has no charge.
Answer: Chemical bond formed when one or more electrons are transferred from one atom to another.
Explanation: Give me the brainiest
weight is a flawed measure of mass because it.... PLEASE ANSWER BY 10/30/21 or a. s. a. p.
Answer:
I believe it's because it's based on gravity
Explanation:
mass is like your true weight while weight is your mass and some equation with gravity. it's been a few years
if you are positive on the answer please help - can you see the horsehead nebula from earth - no links pls !!
Answer:
You can but because it is almost 1500 lightyears away it appears blurry and somewhat hard to find. So the answer to your question is yes but not with the naked eye. You need a telescope lens to see it as more than a blurry spot in the sky.
Explanation:
A container has 1.50 moles of hydrofluoric acid molecules, a deadly acid that
can kill someone in minutes. How many molecules is this?
A container has 1.50 moles of hydrofluoric acid molecules, a deadly acid that can kill someone in minutes molecules are 9.03 × 10 ²³ molecules.
What are moles?Moles are the smallest unit of a molecule that participates in the formation of the molecules to compete in a reaction and the value will be equal to the Avogadro number 2.303 × 10 ²³.
To calculate the total number of molecules the value of one mole is 2.303 × 10 ²³. so, for 1.50 moles of hydrofluoric acid will be,
1.50 moles = 2.303 × 10 ²³.moles
hydrofluoric acid molecules = 1.50 × 2.303 × 10 ²³
hydrofluoric acid molecules = 9.03 × 10 ²³ molecules.
Therefore, 9.03 × 10 ²³ molecules are present in the container has 1.50 moles of hydrofluoric acid molecules, a deadly acid that can kill someone.
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why don't electrons, which are attracted to the protons in the nucleus, simply fall into the nucleus?
Answer:
electrons are fermions, they can only access an energy level if it has not already been occupied by another electron. Thanks to this principle, there is a minimum energy level within the atom and it is not possible for an electron to collapse to the nucleus because it cannot exceed this} threshold.
Explanation:
I hope I have helped you.
Why do you think lone pairs of electrons create greater repulsion when located near other
lone pairs or bonding pairs? Orbitals containing lone pairs of electrons require more space
than orbitals containing bonding pairs. Why do you think this is the case? What does the
presence of one or more lone pairs of electrons do to the bond angles in a molecule (in other
words, do bond angles get larger, smaller, or remain unchanged?)
When there are lone pairs on the valence shell of the central atom in a molecule, the bond angle is decreased.
The shape of molecules depend on the number of electron pairs on the valence shell of the molecules. These electron pairs could be lone pairs or bond pairs. Lone pairs occupy more space around the central atom since it is attracted to only one nucleus compared to bond pairs which are attracted to two nuclei.
When lone pairs are present on the central atom in a molecule, they tend to "squeeze" the molecule thereby decreasing the bond angle in the molecule. Hence, presence of one or more lone pairs of electrons make the bond angles get smaller.
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a molecule that carries information across a synaptic cleft is a
Can you answer my question in SCIENCE... Directions: Below are the reactants and products of photosynthesis. Choose the chemical symbol that matches the word.
Answer:
Water :H2O
Carbon dioxide :CO2
Oxygen :O2
Glocuse :C6H12O6
Answer:
water = H20
carbon dioxide = CO2
oxygen = 02
glucose= C6H1206
Explanation:
Which statement is true about oxygen and rocks?
A) Both are mixtures.
B) Both are pure substances.
C)Oxygen is a mixture and a rock is a pure substance.
D)Oxygen is a pure substance and rocks are mixtures.
Answer: both are mixtures , Brainliest please
Explanation:
Answer:
C) is the correct answer
PLEASE HELP NEED ANSWER FAST
RATES OF WEATHERING LAB
Purpose:
The purpose of this lab report is to _______.
Question:
(What is the overall question you are trying to answer?)
Procedures:
(Here you will copy the lab directions over)
Data Tables:
Analysis and Conclusion:
In conclusion relative and absolute dating (or whatever your lab was about)…
Answer:
communicate the important work you have done in lab
Explanation:
Which immunization is available to prevent communicable disease and illness?WILL MARK BRAINLIEST 30 PTS
bronchitis
diabetes
measles
strep throat
Measles is a communicable disease that requires immunization to prevent illness when exposed to it.
Measles is a communicable disease and highly contagious. It is usually very serious in children. The disease can be contacted through droplets in the air, physical contact and through mother-to-child transmission.
It is a very serious disease as it is caused by a virus which replicates very fast in the throat and nose thereby creating symptoms such as runny nose, coughing, sneezing and is usually accompanied with a rash.
The severity and death rates is what gave rise to the creating of a measles vaccine which is usually given to babies after birth to make them immune to the potential exposure to the virus.
Diabetes, bronchitis and strep throat have no vaccine as they can always be treated or managed with over-the-counter drugs.
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Occurs between a metal atom and a nonmetal atom.
Options:
Ionic Bond or Covalent Bond?
What element has the electron configuration 1s22s22p63523p64523d4?
A.Chromium (Cr)
B.Magnesium (Mg)
C.Manganese (Mn)
D.Iron (Fe)
Answer:
B.Magnesium(Mg)
Explanation:
maybe