2. Report each of the following quantities to 3 significant figures. Use standard notation if possible, or
exponential notation if standard notation won't work.
a. 86,942
f. 56,018
b. 0.00621875
g. 0.003870
c. 107062.03
h. 15.9994
d. 4.00049
i. 12.011
e. 96
j. 2,000
Answer:
a. 86,942 = 8.69x10⁴
f. 56,018 = 5.60x10⁴
b. 0.00621875 = 6.22x10⁻³
g. 0.003870 = 3.87x10⁻³
c. 107062.03 = 1.07x10⁵
h. 15.9994 = 16.0
d. 4.00049 = 4.00
i. 12.011 = 12.0
e. 96 = 9.60x10¹
j. 2,000 = 2.00x10³
Explanation:
Hello,
In this case, rounding off each measurement to three significant figures, considering that if the fourth figure is five or more, the third one is rounded, we obtain:
a. 86,942 = 8.69x10⁴ (four places until the last digit and third digit is not rounded).
f. 56,018 = 5.60x10⁴ (four places until the last digit and third digit is not rounded).
b. 0.00621875 = 6.22x10⁻³ (three places until the first digit and third digit is rounded).
g. 0.003870 = 3.87x10⁻³ (three places until the first digit and third digit is not rounded).
c. 107062.03 = 1.07x10⁵ (five places until the last non-decimal digit and third digit is not rounded).
h. 15.9994 = 16.0 (those consecutive nines round the number to 16.0).
d. 4.00049 = 4.00
i. 12.011 = 12.0
e. 96 = 9.60x10¹ (exponential notation is needed since the number initially has two significant figures so an additional zero is added)
j. 2,000 = 2.00x10³ (three places until the last digit and third digit is not rounded).
Best regards.
The first health care worker said, "Anatomy and Physiology makes the difference between me being a nurse and a ______ nurse?
Answer
The first health care worker said, "Anatomy and Physiology makes the difference between me being a nurse and a great nurse?
Explanation:
I got the correct answer
Please help me with this? :(
Answer:
1. Diagram C.
2. Diagram A.
Explanation:
1. Calcium atom, Ca has 20 protons and 20 electrons. On the other hand, Calcium ion, Ca^2+ has 20 protons and 18 electrons. This is true because the +2 charge on the calcium ion, Ca^2+ indicates that the calcium atom, Ca has loss 2 electrons.
From the above illustration we can say that calcium ion, Ca^2+ has the following:
Proton = 20
Electron = 18
Therefore, diagram C indicates calcium ion, Ca^2+.
2. Fluorine atom, F has 9 protons and 9 electrons. Fluoride ion, F¯ has 9 protons and 10 electrons. This is so because the –1 charge on the fluoride ion, F¯ indicates that the fluorine atom, F has gained 1 electron.
Thus, we can say that the fluoride ion, F¯ has the following:
Proton = 9
Electron = 10
Therefore, diagram A represent fluoride ion, F¯.
What is the symbol for the element that has 12 protons,14 neutrons, and 12 electrons
Answer:
mg
Explanation:
Zirconium dioxide (ZrO2), sometimes known as zirconia, is a white crystalline oxide of zirconium. It can be used in oxygen sensors and fuel cell membranes because it has the ability to allow oxygen ions to move freely through the crystal structure at high temperatures. The ionic radius of Zr is 0.079 nm, and the ionic radius of Cl is 0.140 nm. What is the coordination number of ZrO2?a. 3b. 6c. 4
Answer:
The coordination number of ZrO₂ = 6
Explanation:
A crystal structure is determined by the ratio of ionic radii of the positive and negative ions present in the crystal.
The ratio of the radii of the positive(cations) and negative(anions) is called the limiting radius ratio and it gives the coordination number of the crystal.
Limiting radius ratio = radius of cation/radius of anion
For ZrO₂:
radius of Zr ion (Zr⁴⁺) = 0.079 nm; radius of O ion (O²⁻) = 0.140 nm
Limiting radius ratio = 0.079 nm/0.140 nm = 0.564
From tables, when the limiting radius ratio value is between 0.414 - 0.732, the coordination number is six and the shape of the crystal is octahedral.
Therefore, the coordination number of ZrO₂ = 6
When potassium chlorate decomposes to potassium chloride and oxygen gas is it a physical or chemical change?
Describe each highlighted bond in terms of the overlap of atomic orbitals. (If the highlighted bond is not a pi bond, select the blank option from the dropdown menu.) Compound 1: Molecular orbital type: _________ Atomic orbitals in the sigma bond: _________ Atomic orbitals in the pi bond: _________ Compound 2: Molecular orbital type: _________ Atomic orbitals in the sigma bond: _________ Atomic orbitals in the pi bond: _________
The image of the bonds are missing, so i have attached it.
Answer:
A) - Sigma bond
-Sp³ and Sp³
- None
B) - Sigma and pi bond
- Sp² of C and p of O
- p of C and P of O
Explanation:
A) For compound 1;
- the molecular orbital type is sigma bond due to the end-to-end overlapping.
- Atomic orbitals in the sigma bond will be Sp³ and Sp³
- Atomic orbitals in the pi bond would be nil because there is no pi bond.
B) For compound 2;
- the molecular orbital type is sigma and pi bond
-Atomic orbitals in the sigma bond would be Sp² of C and p of O
- The Atomic orbitals in the pi bond will be; p of C and p of O
Rounding 6.42 g to 2 significant figures
Answer:
6.4
Explanation:
Which of these statements is supported by the results of Thomson’s experiment? Check all of the boxes that apply.
Atoms are indivisible.
Cathode rays are made up of negatively charged particles.
Atoms contain negatively charged particles.
Answer: Cathode rays are made up of negatively charged particles.
Atoms contain negatively charged particles.
The density of water at 40°C is 0.992 g/mL. What is the volume of 2.69 g of water at this temperature? V= mL
Answer:
[tex]\boxed {\tt 2.71169355 \ mL}[/tex]
Explanation:
Density can be found using the following formula:
[tex]d=\frac {m}{v}[/tex]
Rearrange the formula for v. Multiply both sides by v, then divide both sides by d.
[tex]d*v =\frac {m}{v}*v[/tex]
[tex]d*v=m[/tex]
[tex]\frac{d*v}{d}=\frac{m}{d}[/tex]
[tex]v=\frac{m}{d}[/tex]
The volume can be found by dividing the mass by the density. The mass is 2.69 grams and the density is 0.992 grams per milliliter.
[tex]m= 2.69 \ g\\d= 0.992 \ g/mL[/tex]
Substitute the values into the formula.
[tex]v=\frac{2.69 \ g}{0.992 \ g/mL}[/tex]
Divide. Note that the grams, or g, will cancel each other out.
[tex]v=\frac{2.69}{0.992 \ mL}[/tex]
[tex]v= 2.71169355 \ mL[/tex]
The volume of the water is 2.71169355 milliliters.
In a compound the elements are _____ together, whereas in a mixture the substances are blended together.
Answer:
bonded
Explanation:
Compounds are two elements bonded together.
A mixture is multiple substances blended together. The substances aren't bonded together and can easily be extracted from each other.
what element has 3 protons 2 neutrons and 2 electrons
Answer:
helium i think
Explanation:
The Avogadro constant is defined as
Answer:
Hope this may help you
indigestion tablets neutralise acid in the stomach. what does this tell you about indigestion tablets?
Answer:
It is basic.
Explanation:
Bases can neutralize acids.
You bought a new car and estimated that your monthly payment would be $312. However, your actual payment amount is $325. How much error was in your estimate?
Identify the type of chemical reaction taking place in the following and write in balanced equation from
a) Barium Chloride mixed with copper sulphate solution and a white precipitate is observed b) On heating green colour sirf ferrous sulphate crystals reddish brown solid left and smell of gas having order of burning sulphur is produced.
Answer:
a. The balanced chemical equation is written below and this is a type of double displacement reaction.
Explanation:
When barium chloride reacts with copper sulfate, a white precipitate of barium sulfate is observed.
The chemical equation for the reaction of barium chloride and copper sulfate follows:
b.
2FeSO4--(heat)---> Fe2O3 + SO2+ SO3
This Reaction is an example of Thermal Decomposition Reaction.
Select the answer from the drop-down, ranging from true or false.
Mixtures have components that are always in fixed ratios.
[ true or false ]
Compounds can only be separated physically.
[ true or false ]
The components of a mixture keep their unique properties.
[ true or false ]
Mixtures can be physically separated
[ true or false ]
Mixtures are pure substances
[ true or false ]
Compounds are pure substances
[ true or false ]
Answer:
False, False, True, True, False, True
Explanation:
Mixtures have components that are always in fixed ratios. FALSE. The ratio of components in a mixture is variableCompounds can only be separated physically. FALSE. Compounds can only be separated chemically.The components of a mixture keep their unique properties. TRUE. Mixtures can be physically separated. TRUE. Mixtures are pure substances. FALSE. Mixtures are formed by a mixture of 2 or more pure substances, not bonded chemically.Compounds are pure substances. TRUE.true? no false. ... no its true uhhhhh no gotta be false true. false. true. fase. gotta be tru false or maybe its true? nah its false
pls brainliest?
PLEASE HELP ME, I have no idea how to do this :(
Answer:
molar mass: 151.165
Explanation:
mass of Carbon is 12.011 amu
mass of Hydrogen is 1.008
mass of Nitrogen is 14.007
mass of Oxygen is 15.999
you make the calculations like this...
[tex](12.011 \times 8) + (1.008 \times 9) + (14.007) + (15.999 \times 2) = 151.165amu[/tex]
Catie set a glass of hot water and a glass of cold water on the kitchen table and let them sit for one hour. How will the particle motion within the glasses change?A.The particles in both glasses will speed up.B.The particles in both glasses will slow down.C.The particles in the hot water will slow down, while the particles in the cold water will speed up.D.The particles in the hot water will speed up, while the particles in the cold water will slow down.
Answer:
C.The particles in the hot water will slow down, while the particles in the cold water will speed up
Explanation:
Heat causes changes in the molecules of substances when applied to them. The molecules of water, as a case study used in this question, when heated has an increased kinetic energy which causes its particles to move faster i.e. speed up. Also, when water is freezed or cold, it's particles move slower i.e. slow down due to decreased kinetic energy.
Hence, when a hot glass of water and a cold glass of water are placed on a kitchen table for 1 hour, they don't remain in their respective thermal state.
- The hot water (with an increased movement of molecules) begin to cool down, hence, its particles slows down as it gets cold or less hot.
- Likewise, the cold water (with a decreased movement of molecules) begins to get warmer, hence, it particles speedens up as it gets warmer.
Therefore, The particles in the hot water will slow down, while the particles in the cold water will speed up
Question 1 (Multiple Choice Worth 2 points)
(01.01 LC)
The strength of gravitational force is affected by the distance between objects and which of the following?
O Weight
O Speed
O Density
O Mass
3.0 moles of nitrogen is reacted with 11.0 moles of hydrogen to produce ammonia according to the chemical equation shown below. Which one of the following statements is false?
N2(g) + 3 H2(g) → 2 NH3(g)
a. Hydrogen is the excess reactant.
b. 2.0 moles of hydrogen are left over.
c. 12.0 moles of ammonia are produced.
d. Nitrogen is the limiting reactant.
Answer:
c
Explanation:
From the equation, we can say that we need thrice the number of hydrogen than that of nitrogen
we are given 3 moles of nitrogen and 11 moles of hydrogen
but thrice the number of moles of nitrogen is 9, hence we have hydrogen in excess or Hydrogen is the excess reagent
Since we had 11 moles of Hydrogen and we only needed 9, 2 moles of hydrogen are left over
From the equation, we can see that the moles of ammonia formed will be twice the moles of nitrogen
Since 3 moles of nitrogen are used, the reaction will give us 6 moles of Ammonia and NOT 12 moles, therefore c is the correct answer
Since we have hydrogen in excess, our reaction is being limited because we have less Nitrogen, Hence Nitrogen is the Limiting Reagent
Option C is the only false statement
The false statement is that "12.0 moles of ammonia are produced"
According to the equation of reaction:
N₂ + 3H₂ >>>>> 2NH₃
1 mole of N₂ reacts with 3 moles of H₂
3 moles of N₂ will react with 9 moles of H₂
Since 3 moles of N₂ is said to react with 11 moles of H₂ (instead of 9 moles of H₂), H₂ is in excess by 2 moles. That is, N₂ is the limiting reactant.
Since N₂ is the limiting reactant:
1 mole of N₂ produces 2 moles of NH₃
3 moles of N₂ will produce 6 moles of NH₃
Therefore, we can conclude that:
Hydrogen is the excess reactant2.0 moles of hydrogen are left overNitrogen is the limiting reactantLearn more here: https://brainly.com/question/19555927
1. How many ATOMS of carbon are present in 7.48 grams of carbon monoxide ?
Answer:
The answer is 1.61 × 10²³ atoms
Explanation:
To determine number of atoms, we will use the formula below
Number of atoms = number of moles (n) × avogadro's constant (6.02 x 10²³)
n was not provided, hence we will solve for n
n = mass/ molar mass
molar mass of carbon monoxide, CO (where C is 12 and O is 16) is 12 + 16 = 28
mass was provided in the question as 7.48
n = 7.48/28
n = 0.267
Hence,
number of atoms = 0.267 × 6.02 x 10²³
= 1.61 × 10²³ atoms
can some one help The function of the cell wall in a plant cell is Question 2 options: Allowing material to pass in and out of the cell Uses carbon dioxide, water and energy from the sun to make sugar Breaks sugar down into ATP which the cell can use for energy Provides support and protection for the cell
Answer:
the protection one
Explanation:
the cell wall acts a barrier
I am timed please help
Answer:
compound
Explanation:
MgO is an inorganic compund :) The simplest explanation is that it's not an element b/c there's two elements (Mg & O) in the substance, and it's not a mixture b/c you can't easily separate the two elements.
Answer:
magnesium when magnesium is burnt by heat it forms an compound called magnesium oxide
If a boy was standing on his head, his mouth would be ___ to his nose.
Answer:
The correct answer is "inferior".
Explanation:
In anatomy, the term inferior is used to describe parts of the body that are below other part used as reference. Inferior comes from the Latin "inferus" that means "below". In this case, the mouth will always be inferior to the nose, it doesn't matter if the boy was standing on his head or if he is in other position.
Answer:
correct answer, inferior.
Explanation:
of little or less importance, value, or merit always felt inferior to his older brother. 2a : of low or lower degree or rank. b : of poor quality : mediocre. 3 : situated lower down : lower.
If one person is regarded as inferior to another, they are regarded as less important because they have less status or ability. He preferred the company of those who were intellectually inferior to himself.
Hope this helped!
a nucleus with 4 protons has a positive charge of _____ PLEASE LET ME KNOW
Answer:
if were talking about berylium then the answer should be 2 because it wants to move 2 spaces back (losing electrons) to become a nobel gas so the answer is 2+
Explanation:
it has 2 valence electrons YW :)
A nucleus with 4 protons has a positive charge of +2.
What are Protons?Protons may be defined as the type of sub-atomic particles that are present in the nucleus of an atom along with the neutrons. These sub-atomic particles possess a positive charge in nature. It may be thought that protons are discovered by Ernest Rutherford.
Beryllium has a nucleus with 4 protons, which means that it has an atomic number of 4. This element belongs to the alkaline earth metals in group 2. Beryllium has the capability to lose two electrons in order to attain a noble gas configuration and occupy stability. It has an electronic configuration [tex]1s^2, 2s^2[/tex]. So, in order to make it octet fulfilled, it loses two electrons and becomes positively charged.
Therefore, a nucleus with 4 protons has a positive charge of +2.
To learn more about Protons, refer to the link:
https://brainly.com/question/1805828
#SPJ2
A laser pointer used in the classroom emits light at 5650 Å, at a power of 4.00 mW. (One watt is the SI unit of power, the measure of energy per unit of time. 1 W = 1 J/s). How many photons are emitted from the pointer in 115 seconds?
Answer:
n = 1.3 x 10¹⁸ photons
Explanation:
First we need to calculate the amount of energy released in given time:
E = Pt
where,
E = Energy = ?
P = Power = 4 mW = 0.004 W
t = time = 115 s
Therefore,
E = (0.004 W)(115 s)
E = 0.46 J
Now, this energy can be given in forms of photons as:
E = nhc/λ
where,
n = No. of photons = ?
h = Plank's Constant = 6.626 x 10⁻³⁴ J.s
c = speed of light = 3 x 10⁸ m/s
λ = wavelength of light = 5650 x 10⁻¹⁰ m
Therefore,
0.46 J = n(6.626 x 10⁻³⁴ J.s)(3 x 10⁸ m/s)/(5650 x 10⁻¹⁰ m)
n = (0.46 J)/(3.5 x 10⁻¹⁹ J)
n = 1.3 x 10¹⁸ photons
Answer:
1.308 x 10¹⁸ photons were emitted from the laser pointer.
Explanation:
Given;
wavelength of the photon, λ = 5650 Å = 5650 x 10⁻¹⁰ m
power emitted by the source, P = 4 mW = 4 x 10⁻³ W
time of photon emission, t = 115 s
The energy of a single photon is given by;
E = hf
f = c / λ
[tex]E = \frac{h c }{\lambda}[/tex]
where;
c is speed of light = 3 x 10⁸ m/s
h is Planck's constant = 6.626 x 10⁻³⁴ Js
[tex]E = \frac{(6.626 *10^{-34}) (3*10^8) }{5650*10^{-10}}\\\\ E = 3.518*10^{-19} \ J[/tex]
Energy of the source (laser pointer) = P x t
= (4 x 10⁻³ W) (115 s )
= 0.46 J
If no energy is lost, then emitted energy by the source must be equal to total energy of then photons;
[tex]E_T = n E_{photon}\\\\n = \frac{E_T}{E_{photon}}\\\\n = \frac{0.46}{3.518*10^{-19}}\\\\n = 1.308*10^{18} \ photons[/tex]
Therefore, 1.308 x 10¹⁸ photons were emitted from the laser pointer.
6. Un volumen de 1.0 mL de agua de mar contiene casi 4 x 10-12 g de Au. El volumen total de agua en los océanos es de 1.5 x 1021 L. Calcule la cantidad total de Au (en gramos) existente en los océanos y su valor total en dólares. ( 1 onza = $ 948)
Answer:
The total amount of Au is $ [tex]2.0\times10^{24}[/tex]
Explanation:
Given that,
Mass of 1.0 ml of Au [tex]m=4\times10^{-2}\ g[/tex]
Total volume of water in oceans [tex]V=1.5\times10^{21}\ L[/tex]
We need to calculate the volume in ml
Using given volume
[tex]V=1.5\times10^{21}\times1000\ mL[/tex]
[tex]V=1.5\times10^{24}\ mL[/tex]
We need to calculate the total mass of Au
Using given data
[tex]1\ ml\ volume = 4\times10^{-2}\ g[/tex]
[tex]1.5\times10^{24}\ ml=4\times10^{-2}\times1.5\times10^{24}[/tex]
So, The total mass of Au is [tex]6\times10^{22}\ g[/tex]
The mass will be in ounce,
[tex]Mass=0.035274\times6\times10^{22}[/tex]
[tex]Mass=2.12\times10^{21}\ ounce[/tex]
The total amount of the Au Will be
[tex]Total\ amount=2.12\times10^{21}\times948[/tex]
[tex]Total\ amount=2.0\times10^{24}[/tex]
Hence, The total amount of Au is $ [tex]2.0\times10^{24}[/tex]
11. A sample contains 25% water and weighs 201 grams. Determine the grams of water in the
sample.
Answer:
[tex]m_{water}=50.25g[/tex]
Explanation:
Hello,
In this case, considering that the by-mass percent of water is:
[tex]\% m/m=\frac{m_{water}}{m_{sample}}*100\%[/tex]
Given such percent and the mass of the sample, we can find the mass of water in grams in the sample by solving for it as shown below:
[tex]m_{water}=\frac{\%m/m*m_{sample}}{100\%}\\ \\m_{water}=\frac{25\%*201g}{100\%}\\ \\m_{water}=50.25g[/tex]
Best regards.
How many Calories are there in 4600 Joules?
Answer:
1099.426
Explanation: