Answer:
d or c
Explanation:
Answer:
c
Explanation:
did it
a. What is the mass in grams of 4.2 mols of FeO2?
According to mole concept, there are 368.928 g mass in 4.2 moles of FeO₂.
What is a mole?Mole is defined as the unit of amount of substance . It is the quantity measure of amount of substance of how many elementary particles are present in a given substance.
It is defined as exactly 6.022×10²³ elementary entities. The elementary entity can be a molecule, atom ion depending on the type of substance. Amount of elementary entities in a mole is called as Avogadro's number.
It is widely used in chemistry as a suitable way for expressing amounts of reactants and products.For the practical purposes, mass of one mole of compound in grams is approximately equal to mass of one molecule of compound measured in Daltons. Molar mass has units of gram per mole . In case of molecules, where molar mass in grams present in one mole of atoms is its atomic mass.
Number of moles=mass/molar mass
Thus, mass=4.2×87.84=368.928 g.
Thus, there are 368.928 g mass in 4.2 moles of FeO₂.
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1. What are the trends for atomic size across a period and down a group for the
main group elements?
2. Draw the following Lewis structures:
a) ammonium ion b) sulfur trioxide c) hydrogen cyanide
3. Using formal charge formula (or electronegativity differences), to determine
the following the best structure, OCS, COS or CSO.
Answer:
Here's what I get
Explanation:
1. Trends in atomic size
Atomic size tends to decrease from left to right across the Periodic Table.
You are adding one electron at a time. the electrons repel each other, so the size should increase.
You are also adding a proton to the nucleus. The additional attraction should pull the electrons closer to the nucleus.
The nuclear pull wins, so the atoms get smaller from left to right
Atomic size increases from top to bottom of a Group.
You are adding electrons to an extra shell, so the size should increase.
You are also adding protons to the nucleus, so the size should decrease.
The size of the outer shell wins, so the atomic size increases going down a Group.
2. Lewis structures
(a) Ammonium ion
N is the central atom. The N atom has the positive charge.
(b) Sulfur trioxide
S is the central atom, with a double bond to each of the three O atoms.
(c) Hydrogen cyanide
C is the central atom, with a triple bond to the N atom.
3. COS
The best structure is that of O=C=S. It has no formal charges.
The Lewis structures for the other arrangements have formal charges.
The correct answers of this question is given below.
1. The atomic size increases going down a Group.2. (a) Ammonium ion : The N atom has the positive charge. (b) Sulfur trioxide : Having double bond to each of the three O atoms. (c) hydrogen cyanide : Having a triple bond to the N atom.3. COS and it has no formal charges What is Periodic table?A table in which the chemical elements are arranged in order of increasing atomic number.A periodic table has 118 known elements The chemical elements are arranged from left to right and top to bottom in order of increasing atomic number.What is the explanation for this answers?1. Trends in atomic size : Atomic size tends to decrease from left to right across the Periodic Table.You are adding one electron at a time. the electrons repel each other, so the size should increase.You are also adding a proton to the nucleus. The additional attraction should pull the electrons closer to the nucleus.The nuclear pull wins, so the atoms get smaller from left to right.Atomic size increases from top to bottom of a Group.Adding electrons to an extra shell, so the size should increaseAdding protons to the nucleus, so the size should decrease.The size of the outer shell wins, so the atomic size increases going down a Group.2. Lewis structures :
(a) Ammonium ion : N is the central atom. The N atom has the positive charge. (b) Sulfur trioxides : S is the central atom, with a double bond to each of the three O atoms.(c) Hydrogen cyanide: C is the central atom, with a triple bond to the N atom3. COS
The best structure is that of O=C=S. It has no formal charges.The Lewis structures for the other arrangements have formal charges.Learn more about atomic size below,
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In the reaction N2 + 3H2 - 2NH3, how many
grams of H, are needed to produce exactly I mole
of ammonia?
A. lg
B. 2g
C.3g
D.4g
Answer:
B. 2g
Explanation:
So first you have to find the mole to mole ratio then convert it to grams if that makes sense. So the mole to mole ratio is 2 ammonia to 3 hydrogen gas. So then after you do that conversion you can solve for grams then. Sorry I am not that great at explaining.
What specifically do vaccines contain which cause your body to become
immune to specific pathogens? *
Answer:
I'm not entirely sure, but I've heard that vaccines contain very weak amounts of the virus in order to expose your body to it, so that your body can become immune to it before being exposed to the real thing.
So basically, a flu shot contains a weak version of influenza.
I don't know this for sure, but hopefully this helps!
I need the correct answer
Answer:
d.
Explanation:
They can be spread through contaminated surfaces.
Answer:
d
Explanation: pathogens csnnot be spread be sontaminated surfesec
Which planet do scientists believe prevented the asteroids in the asteroid belt from forming a planet? Earth Jupiter Mars Neptune
Answer:
Jupiter
Explanation:
Jupiter prevented any planetary bodies from forming in the gap between Mars and Jupiter, thats why asteroids collide today.
sorry if its wrong .
Answer:
Your answer is Jupiter
Explanation:
I TOOK THE TEST AND I LEARNED THIS
An exothermic reaction releases 13,450J of heat. How many calories of energy are released? A) 5 56,274 calories B)1,244 caloriesC) 134,500 caloriesD) 3,215 calories
Answer:
The correct option is;
D) 3,215 calories
Explanation:
Here we are required to convert 13,450 J to calories
1 calorie is the amount of heat required to raise the temperature of 1 gram of water by 1°C
Therefore, 1 calorie = 4.184 Joules
Hence, 1 Joule = 1/4.184 calorie for which we have;
13,450 J = 13,450 × 1/4.184 calories = 13,450/4.184 calorie
13,450 J = 3,214.63 calories
Rounding up to the nearest whole number, we have;
13,450 J ≈ 3,215 calories.
Is amylopectin a straight chain polysaccharide
Answer:
hey friend, Amylopectin is a branched chain.
60.0 g of NH Cl are dissolved in 100 grams of water at 60.0° C. This solution is
A
supersaturated
B
saturated
С
unsaturated
D
none of the above
Answer:
B) is the correct answer
A chemist needs 2.00 liters of hydrochloric acid. How many pints is this?
Answer:
4.22675
Explanation:
If a buffer has an initial pH of 6.34 and the acid has a Ka of 3.46 × 10-4, what is the ratio of conjugate base to weak acid in the buffer system?
Answer: The ratio of conjugate base to weak acid in the buffer system is 758 : 1
Explanation:
The dissociation constant for acid = [tex]K_a=3.46\times 10^{-4}[/tex]
pH = 6.34
First we have to calculate the value of [tex]pK_a[/tex].
The expression used for the calculation of [tex]pK_a[/tex] is,
[tex]pK_a=-\log (K_a)[/tex]
Now put the value of [tex]K_a[/tex] in this expression, we get:
[tex]pK_a=-\log (3.46\times 10^{-4})[/tex]
[tex]pK_a=3.46[/tex]
Now we have to calculate the ratio of conjugate base to weak acid in the buffer system
Using Henderson Hesselbach equation :
[tex]pH=pK_a+\log \frac{[\text {conjugate base}]}{[Acid]}[/tex]
Now put all the given values in this expression, we get:
[tex]6.34=3.46+\log \frac{[\text {conjugate base}]}{[Acid]}[/tex]
[tex]\frac{[\text {conjugate base}]}{[Acid]}=758[/tex]
Therefore, the ratio of conjugate base to weak acid in the buffer system is 758: 1
Answer:
A. 1:0.46
Explanation:
I took the test
Which of the following compounds contains covalent bonds? *
Cs₂O
Fe₂O₃
NaCl
CCl₄
NaCI
Explanation:
I just worked this out the day before
which is correct? not sure which is right
Answer:
butane
Explanation:
EMERGENCY: I WILL FAIL: PLS HELP WILL MARK BRAINLIEST JUST PLS HELP
Answer:
condensation: moisture builds up on window; dew forms on blades of grass
deposition: snow is made inside a cloud; frst froms on window?
Explanation:
Question 3 of 10
5 Points
Match the approximate percentage of the world's water to where it is stored.
Salt water
97 percent
Ice caps and
glaciers
2 percent
Fresh liquid
water
1 percent
Answer:
salt water 97%
fresh water 1%
frozen 2%
Explanation:
bases have a pH of
a. more than 7
b. less than 7
c. 7
Answer:
Bases are more then 7
acids are less then 7 neutral is 7 and bases are more than
Answer:
A. More than 7
Explanation:
ph scale, bases are to the right
Describe the interactions with the Sun, Earth and Moon system that result in Lunar Cycle / Phases.
Answer: The tides are another interaction in the sun-earth-moon system. The tides happen because the moon and sun pull on the oceans, causing them to rise and fall each day. The moon has a bigger effect than the sun because it is closer. The angle of the sun as the earth orbits over the course of a year causes the seasons.
Explanation:
How do you convert kilometers to grams
By multiplying the mass value by 1000.
Answer:
Hey!
What you have to do is to multiply the amount of mass * i.e. 67.9g * by 1000 * 67,900kg! *
Explanation:
HOPE THIS HELPS!
After constructing the circuit, Aliyah and Jeremy noticed that the light bulb stays on all the time. This means the batteries will get used up when the flashlight does not need to be on. What is something Aliyah and Jeremy can do to solve this problem?
Answer: Implement a switch
Explanation:
This forms a circuit break or way to easily turn the flow of electricity on or off.
pls help Photosynthesis is used to produce food for plants in the form of glucose. In the process, oxygen is released. As shown in the diagram, plants require water and carbon dioxide (from the air). What else is required for photosynthesis and what role does it play? A) Light is required to provide energy for photosynthesis. B) ATP is required as an energy source for photosynthesis. C) Glucose is required as an energy source for photosynthesis D) Oxygen is required to split water molecules in photosynthesis.
Answer:
A) light is required
Explanation:
ATP, Glucose, and oxygen are created from the process
Which of the following is most likely a homogeneous mixture?
O A. A tossed vegetable salad
B. Chunky peanut butter
O C. Chocolate chip cookies
OD. A vanilla milkshake
Answer:
D)A vanilla milkshake
Explanation:
An insulator,
Keeps electrons inside the nucleus of an atom
Allow electrons to move easily through an object
Is when electrons cannot move through objects easily
Relate dark matter to the development of the universe after the Big Bang. In 3-5 sentences, speculate on how the development of the universe would have been different if there had been no dark matter. In your answer, use the term structures.
Please answer if you do i will mark you as brainliest
Answer:
Without dark matter galaxies would loose an extreme amount of gas required to create stars.
Without dark matter the universe wont have as many galaxies clumped together forming larger versions of those galaxies. This would cause a change in the structure of the "skeleton" of the web.
(Hope this can help, I didn't do exactly as it is said to because that is your job)
:)
Explanation:
Forbes gives somewhat of an explanation if you are curious.
(Ethan Siegal, "The Universe Would Be Very Different Without Dark Matter", Forbes)
Dark matter makes up most of matter in the universe and is found by a quarter of the total composition of the space. After the event of the big bang, the universe expanded and dark matter grew.
Dark matter accounts for about 85% of the matter in the universe. Its presence can be felt in the gravitational effects. Dark matter doesn't interact with the electromagnetic field. After the big bang event, the dark matter still can be found in larger galaxies and contest about 26% of mass-energy and 69% of dark energy. If there had been no dark matter there would be no structure of the cosmic web of galaxies. That is there would be no connection between the galaxies and would remain in isolated fragments.Thus dark matter is a link within and with the comic web.
Learn more about the dark matter and its development-related after the big bang event
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Identity the anode and cathode
Answer:
Pb(s) ---> Pb+2 + 2e- is the anode
Cu+2(aq) + 2e- ---> Cu(s) is the cathode
Which formula represents an alkane?
1.
C2H2
2.
C2H4
3.
C3H4
4.
С3Н8
Answer: Option 4) is correct.
Explanation: It is correct because alkanes have a general formula CnH2n+2. So, all we need to do is substitute and find out how many hydrogens are needed to make the formula an alkane. I am not really good at explaining. I am sorry If I confused you.
Alkanes are the organic compound which has general formula [tex]C_{n}H_{2n +2}[/tex] which satisfies the formula [tex]C_{3}H_{8}[/tex]. Hence [tex]C_{3}H_{8}[/tex] represents an alkane.
AlkaneAlkanes are simplest saturated hydrocarbon. Alkanes are also known as paraffins wax. Alkanes which contains only carbon and hydrogen atoms.
General Formula of AlkaneThe general formula of alkane is [tex]C_{n} H_{2n + 2}[/tex] where n = 1, 2, 3, 4.......
Consider Option 1, [tex]C_{2}H_{2}[/tex] here n = 2 now put the value of n in above formula, we get: [tex]C_{2} H_{2 \times 2 + 2}[/tex] = [tex]C_{2} H_{4 + 2}[/tex] = [tex]C_{2} H_{6}[/tex] , so option 1 does not satisfies the above formula. Hence it is incorrect. Consider Option 2, [tex]C_{2} H_{4}[/tex] here n = 2 now put the value of n in above formula, we get: [tex]C_{2} H_{2 \times 2 + 2} = C_{2} H_{4 + 2} = C_{2} H_{6}[/tex], so option 2 does not satisfies the above formula. Hence it is incorrect. Consider Option 3, [tex]C_{3} H_{4}[/tex] here n = 3 now put the value of n in above formula, we get: [tex]C_{3} H_{2 \times 3 + 2} = C_{3} H_{6 + 2} = C_{3} H_{8}[/tex], so option 3 does not satisfies the above formula. Hence it is incorrect. Consider Option 4, [tex]C_{3} H_{8}[/tex] here n = 3 now put the value of n in above formula, we get: [tex]C_{3} H_{2 \times 3 + 2} = C_{3} H_{6 + 2} = C_{3} H_{8}[/tex], so option 4 satisfies the above formula. Hence it is correct.Thus, from the above conclusion we can see that option 4 [tex]C_{3}H_{8}[/tex] represents an alkane.
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Mosquitoes lays eggs that must hatch in water. The young, called larvae live their first few days in water
Which sentence best describes where you will most likely find mosquitoes and their eggs during the dry season in the Florida Everglades?
A.They will be spread out because water is everywhere.
B.They will be mainly in one area because water is everywhere
C. They will be in fewer areas because water is scarce
D. They will be everywhere because water is scarce.
Answer:
Explanation:
I believe he is C
I need simple answers that a 14-year-old would understand.
What are valence electrons?
What is the difference between the Rutherford and Thompson plum pudding model?
What relative scale for atoms do chemists use? Why do they use this?
Compare and contrast alpha, beta and gamma decay of radionuclides.
Explain why radiation is dangerous for living cells but can be applied to treat people with some forms of cancer.
Explain why oxygen atoms ionise to form the oxide ion with a charge of –2. Identify if oxide is an anion or a cation.
Answer:
1. The Nummber of electrons present in the outermost shell is called Valence electrons.
2. Thomson model:
Thomson model of atom is the model which states that electrons are embedded in a positively charged solid material which is spherical in shape.
Rutherford model
Rutherford model of atom is the model which explains that there is a nucleus in the center of the atom and electrons are located around the nucleus.
3. Relative atomic mass. Atoms have very little mass , so they're difficult to measure accurately. Instead, chemists use a scale. On this scale the mass of a 12C atom is exactly 12.
4. Difference between Alpha, Beta and Gamma radioactive decay:
Alpha decay forms new element with two fewer protons and two fewer neutrons;
Beta decay forms new element with one more proton and one fewer neutron.
Gamma decay forms NO new element, but now the element has less energy because energy is released as gamma rays.
Gamma radiation has the highest penetration power, Beta decay goes the second, alpha decay the last. However, alpha particles make the most damage even if it has the lowest penetration power among the three.
5. This species has a 2− charge on it, so it is an anion. Anions are named using the stem of the element name with the suffix -ide added. This is the oxide anion.
Hope it helps....Pls Mark as Brainliest!! I Have answered all your question in the Simplest way i could...
What element is in group 17 and period 3 of the periodic table?
Answer:
Chlorine is the element located in period 3, group 17 of the periodic table.
Explanation:
Answer: Chlorine
Explanation:
What does a dissolved salt look like?
A. The salt crystals are surrounded by water molecules.
B. The salt crystals separate into salt molecules in the water.
C. The salt separates into ions that settle to the bottom
D. The ions in the salt are surrounded by water molecules.
Answer:
I want to say your answer is B)
The answer is D because the ions in the salt will be surrounded by water molecules
Dissolution in water occurs as a result of ionic interactions. This means that the ions (charged atoms) of the solute has to interact with the ions of water for the solute to dissolve. Based on this principle, only polar compounds can dissolve in water.
According to this question, salt is polar because it contains positive (+) and negative (-) ions. Hence, when placed in water, these ions will interact with the ions of water i.e. H+ and OH-. This causes dissolution of salt in water to form salt solution.
Hence, a dissolved salt will look like "ions in the salt are surrounded by water molecules".
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Which of the following statements is true?
Sound vibrations are changed into electrical impulses by the eardrum.
It is dangerous to listen to sounds over 160 dBs.
High-pitched sounds have low frequencies.
All of the above.
Answer:
all of the above!! :)))
Explanation:
