Answer:
A = 1.627 ×10²³ molecules of CF₂Cl₂.
B = 809.4 ×10²³ molecules of Fe(NO₃)₂.
C = 0.03117 ×10²³ molecules of C₈H₁₈.
D= 1116 ×10²³ molecules of CaO.
Explanation:
A)
Given data:
Mass of CF₂Cl₂ = 32.66 g
Number of moles = ?
Number of molecules = ?
Solution:
Number of moles = mass/ molar mass
Number of moles = 32.66 g/ 120.9 g/mol
Number of moles = 0.2701 mol
Number of molecules:
1 mole = 6.022×10²³ molecules
0.2701 mol×6.022×10²³ molecules / 1mol = 1.627 ×10²³ molecules of CF₂Cl₂.
B) Given data:
Mass of Fe(NO₃)₂ = 24.2 Kg (24.2×1000 = 24200 g)
Number of moles = ?
Number of molecules = ?
Solution:
Number of moles = mass/ molar mass
Number of moles = 24200 g/ 180 g/mol
Number of moles = 134.4 mol
Number of molecules:
1 mole = 6.022×10²³ molecules
134.4 mol×6.022×10²³ molecules / 1mol =809.4 ×10²³ molecules of Fe(NO₃)₂.
C) Given data:
Mass of C₈H₁₈= 0.5912 g
Number of moles = ?
Number of molecules = ?
Solution:
Number of moles = mass/ molar mass
Number of moles = 0.5912 g/ 114.22 g/mol
Number of moles = 0.005176 mol
Number of molecules:
1 mole = 6.022×10²³ molecules
0.005176 mol×6.022×10²³ molecules / 1mol =0.03117 ×10²³ molecules of C₈H₁₈.
D) Given data:
Mass of CaO = 104 Kg (104×1000 = 104,000 g)
Number of moles = ?
Number of molecules = ?
Solution:
Number of moles = mass/ molar mass
Number of moles = 104,000 g/ 56.1 g/mol
Number of moles = 1854 mol
Number of molecules:
1 mole = 6.022×10²³ molecules
1854 mol×6.022×10²³ molecules / 1mol = 1116 ×10²³ molecules of CaO.
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Answer: it is a
Explanation:
which of the following units of measurement would you use to describe the length of your pencil?
Answer:
cm
Explanation:
cm is the most appropriate unit - metres is too big and mm is too small
Which statement best describes a physical change?
Changes can occur to certain chemical properties of the substance, but the overall shape of the substance will remain the same.
Changes can occur to certain physical properties of the substance, but the overall shape of the substance will remain the same.
Changes can occur to physical properties of a substance, but the chemical composition of the substance remains the same.
Changes can occur to chemical properties of a substance, but the chemical composition of the substance remains the same.
Answer:
Physical changes can include changing the colour, shape, state of matter, or volume of a substance.
HELP MEEEEEEEEEEEE
Winds and ocean breezes occur due to _____________.
A. None of these
B. Conduction currents
C. Boiling
D. Convection currents
Answer:
B
Explanation:
it flows by the conduction currents
Hydrogen is in column 1 of the periodic table. What information does this give us? (2 points)
There is one other element that hydrogen will bond with.
There is one neutron in the nucleus.
The mass of the atom is one.
There is one electron in the outer energy level.
Answer:
the last one
Explanation:
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Because hydrogen forms compounds with oxidation numbers of both +1 and -1, many periodic tables include this element in both Group IA (with Li, Na, K, Rb, Cs, and Fr) and Group VIIA (with F, Cl, Br, I, and At).
There are many reasons for including hydrogen among the elements in Group IA. It forms compounds (such as HCl and HNO3) that are analogs of alkali metal compounds (such as NaCl and KNO3). Under conditions of very high pressure, it has the properties of a metal. (It has been argued, for example, that any hydrogen present at the center of the planet Jupiter is likely to be a metallic solid.) Finally, hydrogen combines with a handful of metals, such as scandium, titanium, chromium, nickel, or palladium, to form materials that behave as if they were alloys of two metals.
There are equally valid arguments for placing hydrogen in Group VIIA. It forms compounds (such as NaH and CaH2) that are analogs of halogen compounds (such as NaF and CaCl2). It also combines with other nonmetals to form covalent compounds (such as H2O, CH4, and NH3), the way a nonmetal should. Finally, the element is a gas at room temperature and atmospheric pressure, like other nonmetals (such as O2 and N2).
It is difficult to decide where hydrogen belongs in the periodic table because of the physical properties of the element. The first ionization energy of hydrogen (1312 kJ/mol), for example, is roughly halfway between the elements with the largest (2372 kJ/mol) and smallest (376 kJ/mol) ionization energies. Hydrogen also has an electronegativity (EN = 2.20) halfway between the extremes of the most electronegative (EN = 3.98) and least electronegative (EN = 0.7) elements. On the basis of electronegativity, it is tempting to classify hydrogen as a semimeta
The number of yeast cells in a laboratory culture increases rapidly initially but levels off eventually. The population is modeled by the function а n = f(t) = 1 + be-0.90 where t is measured in hours. At time t = 0 the population is 30 cells and is increasing at a rate of 24 cells/hour. Find the values of a and b. a = b = According to this model, what happens to the yeast population in the long run? O The yeast population will shrink to 0 cells. The yeast population will stabilize at 270 cells. The yeast population will stabilize at 135 cells. The yeast population will stabilize at 8 cells. O The yeast population will grow without bound.
Answer:
Explanation:
[tex]n=f(t)= \frac{a}{(1+be^{-.9t})}[/tex]
At t = 0
30 = [tex]\frac{a}{1 + b }[/tex]
30 + 30 b = a
[tex]\frac{dn}{dt} =f(t)= \frac{-.9abe^{-.9t}}{(1+be^{-.9t})^2}[/tex]
For t = o
[tex]\frac{dn}{dt} =f(t)= \frac{.9ab}{(1+b)^2}[/tex]
given
24 = [tex]\frac{.9ab}{(1+b)^2}[/tex]
24 = [tex]\frac{30\times.9b }{1+b}[/tex]
24 = 27b / 1 + b
24 + 24 b = 27 b
24 = 3 b
b = 8
a = 30 + 30 x 8 = 270
[tex]n=f(t)= \frac{a}{(1+be^{-.9t})}[/tex]
Put t = infinity
n = a = 270
So at infinite time yeast population will stabilise at number 270 .
can someone explain what radioisotopes are?
Answer:
A radioisotope is a radioactive isotope.
Explanation:
On the Periodic Table, elements 92 and up are radioactive. So that is Uranium and any higher elements. Remember that radioactive elements love to decay and are dangerous.
Isotopes are different forms of an element. For instance, we could have different amount of neutrons in the same element (same number of protons).
We could have an element like He - 4 vs. He - 6, where He - 4 would have 2 neutrons and He - 6 would have 4 neutrons.
So a radioisotope would be an elemental isotope that is radioactive. A good example of this is Uranium.
We have thousands of different isotopes of Uranium, but 2 are well known: Uranium - 235 and Uranium - 238. Both are the same element with the same amount of protons, but both have a different amount of neutrons.
name the following alkynes
Explanation:
1) 3,4-dimethyl hex-1,5-diyne
2) 3,3-diethyl pent-4-yn-1-ene
3) 5-(1'-ethyl-2',3'-dimethyl propane) dec-1,3-diyne
tectonic plates move to
Answer:
I don't really understand, but here is my answer:
Tectonics plates can move back and forth, side to side, and into each other which causes earthquakes.
Hope this helps!
Sky
A sample of matter is made up of three different atoms that are chemically combined. What
type of matter is it? How do you know?
Answer:
liquid
Explanation:
a molecule consists of different atoms chemically combined. A molecule is also a liquid. Molecules make up ice cubes, which are also small water particles which arr yet again liquid.
Can yall plz help me!!!!!!!!!!!!
Define the terms below:
● Axis:
● Rotation:
● Revolution:
● Elliptical Orbit:
Answer:
Axis
Anatomy
In anatomy, the second cervical vertebra of the spine is named the axis or epistropheus. By the atlanto-axial joint, it forms the pivot upon which the first cervical vertebra, which carries the head, rotates.
Rotation
A rotation is a circular movement of an object around a center of rotation. A three-dimensional object can always be rotated about an infinite number of imaginary lines called rotation axis. If the axis passes through the body's center of mass, the body is said to rotate upon itself, or spin.
Revolution
In political science, a revolution is a fundamental and relatively sudden change in political power and political organization which occurs when the population revolts against the government, typically due to perceived oppression or political incompetence.
Elliptic orbit
In astrodynamics or celestial mechanics, an elliptic orbit or elliptical orbit is a Kepler orbit with an eccentricity of less than 1; this includes the special case of a circular orbit, with eccentricity equal to 0. In a stricter sense, it is a Kepler orbit with the eccentricity greater than 0 and less than 1.
:) gimme a crown plz
Pls fill in the blank
Because it can either lose or share electrons when it combines with has some of the properties of metals and
other elements, each has some of the properties of nonmetals.
A. Metalloids
B. Sodium
C. Gold
A. Metalloids
They can either lose an electron or share an electron when it combines with other elements. They have some properties of metals and some properties of non-metals.
How many inches are in 4 yards? ( 1 yard = 3 ft and 1 ft = 12 inches)
Answer:
There are 144 inches in 4 yards.
Hope this helps :)
Explanation:
Answer: 144
Explanation:
a screwdriver has a volume of 0.418 cubic centimeters. it also has the mass of 2.3 grams. what is the screwdrivers density
Answer:
The answer is 5.50 g/cm³Explanation:
The density of a substance can be found by using the formula
[tex]density = \frac{mass}{volume} \\ [/tex]
From the question we have
[tex]density = \frac{2.3}{0.418} \\ = 5.50239234...[/tex]
We have the final answer as
5.50 g/cm³Hope this helps you
Answer:
Comets are cosmic snowballs of frozen gases, rock and dust that orbit the Sun. When frozen, they are the size of a small town. When a comet's orbit brings it close to the Sun.
Explanation:
This chart shows characteristics of three different types of atoms.
A 3-column table with one row titled valence electrons in three types of atoms. The first column labeled Atom X has entry 6 valence electrons. The second column labeled Atom Y has entry 2 valence electrons. The third column labeled Atom Z has entry 8 valence electrons.
Which statement is best supported by the information in the chart?
Atom X will donate electrons to Atom Y.
Atom X will accept electrons from Atom Y.
Atom Y will accept electrons from Atom Z.
Atom Z will donate electrons to Atom X.
Answer is Atom X will accept electrons from Atom Y.
Atom X will accept electrons from Atom Y.
What is Chart?
The official 511 traveller information service for Maryland is CHART Web. Maryland 511 gives drivers dependable, up-to-date information about traffic, road closures, and weather-related traffic events and conditions.
When driving in Maryland, MD 511 assists drivers in getting to their destination in the safest and most effective way possible.
The term "chart" (sometimes referred to as "graph") refers to a graphical representation of data visualization in which "the data is represented by symbols, such as bars in a bar chart, lines in a line chart, or slices in a pie chart".
Therefore, Atom X will accept electrons from Atom Y.
To learn more about chart, refer to the link:
https://brainly.com/question/15507084
#SPJ7
6. In our modern times, the atom can be subdivided into
A.) protons and electrons, only
B.) protons and neutrons, only
C.) protons, neutrons, and electrons, only
D.) neutrons and electrons, only
Answer:
C.) protons, neutrons, and electrons, only
Explanation:
According to the modern atomic theory, we can distinguish 2 parts in an atom:
The nucleus, where is the majority of the mass of the atom, that is, protons and neutronsThe external shell, where are the electrons.In a neutral atom, there are the same number of protons (positive charges) as electrons (negative charges).
Why the noble gases are found in small amounts in the earth's atmosphere?
Answer:
They have completely filled outermost shell
Explanation:
The noble gases are the rarest and occur in trace amounts in the atmosphere because they have completely filled outermost and this makes them unreactive with other elements.
Elements become abundant as they combine with other species to form compounds.
Noble gases on the other hand have a high level of stability and do not readily combine with other species.
Some of these gases are :
Helium
Neon
Argon
Krypton
Xenon
Radon
They have very high ionization energy and very low electron affinity and so will not readily react.
Which phrase describes a metamorphic rock?
formed from a volcano
was once buried underground
formed from evaporating water
contains minerals that have not changed
Answer:
C: was once buried underground
Explanation:
Hope this helps!
Answer:
The correct answer you are looking for is B i have got 100% on this test.
Explanation:
hop this helps! └(^o^)┘ ↖(^ω^)↗
The Periodic Table of elements is arranged by:
O atomic mass
O number of neutrons
O number of electrons
O atomic number
Option D, atomic number is the correct answer
Answer:
D. Atomic Number
Explanation:
All of the elements in the periodic table are arranged according to their atomic number.
N= 0.785 mol N2
P= 1.5 atm
T= 301 K
V=?
FAST PLZ
Answer:
V=13.031L
Explanation:
Use the equation PV=nRT. n is moles, R is 8.31, T is temp in (K), and Pressure in KPa
Maria wants to determine which type of disinfectant kills the most bacteria.
Which of the following is the best way for Maria to determine this?
A.
Interview ten different people to determine which type of disinfectant they prefer.
B.
Put the same amount and species of bacteria on ten identical plates, and add ten different kinds of disinfectant to each plate.
C.
Ask ten different companies that make disinfectants which type is best.
D.
Put the same amount and species of bacteria on ten identical plates, and add a different disinfectant to each plate.
A I think thats what I would put
A student redid the experiment of mixing room-temperature water and warm
water. This time, she doubled the amount of room temp water. How will the final
temperature be different?
A- It will be higher, because the amount of water in the mixture is greater.
B-It will be lower, because the temperature of the room-temperature water will not increase as much.
C-It will be the same because all parts of the mixture will end up at the same temperature.
D-It will be higher, because all parts of the mixture will end up at the same temperature.
Answer:
B) It will be lower, because the temperature of the room-temperature water will not increase as much.
Explanation: I took the test
which two formulas represent compounds?
A.NaCI
B.HCI
C.H2
D.Ag
Answer: A and B
Explanation: A and b are Sodium chloride and Hydrogen chloride which are both compounds.
Answer: A. NaCI
Explanation: APEX
PLEase help i will give brainliest
Consider the information provided in experiment #3 Figure 2. Three different variables are compared for C3H8 (propane) and H2O (water). The strength of the intermolecular forces are responsible for the behavior of the two compounds.
Identify the intermolecular force for the two compounds.
Which one is stronger?
Explain how the strength of intermolecular forces plays a role in at least two of the properties (volatility, boiling point, or surface tension) for C3H8 (propane) and H2O (water).
Cite evidence from the data to explain your reasoning.
Experiment #3: The student follows study #2 with a comparison of propane (C3H8) and water. Volatility is the tendency for a substance to vaporize and it was found that propane vaporizes quickly while water vaporized slowly. Surface tension is a physical property equal to the amount of force per unit area necessary to expand the surface of a liquid. It is this phenomenon which allows a water strider or lizard to run across the surface of water.
Answer:
what kind of school u doin? lol
what are twoparts of an atom
How many atoms are present in 48.60 g ofMg
Answer: Explanation:
There are 6.02 x 10^23 atoms in 1 mol.
How long does it take for the water to start boiling? At what temperature does the water boil?
Answer:
At sea level, or at zero feet in altitude, the boiling point of water is at 212 °F (100 °C). Once the water has reached this boiling point, the US Center for Disease Control recommends keeping it at a rolling boil for about a minute to make sure it is purified.
Answer:
Water boils at 212 degrees fahrenheit or 100 degree celcius
Explanation:
its true
which natural disaster is most unpredictable?
Answer:
Explanation:
Earthquakes
Earthquakes: Nature's most unpredictable and one of her most devastating natural disasters.
Answer:
Earthquake
Explanation:
Because we have not discovered any high techto predict it, In 2011 a 9.0 earthquake hit the coast of Sendai they had no warning
What is the underlying, fundamental force for the formation of all chemical bonds?
A detailed explanation would be best, please.
Answer:
[tex]it \: is : \\nuleic\: force\: of\: ( attraction \: and \: repulsion).[/tex]
Explanation:
[tex]this \: is \: because, \: for \: any \: type \: of \: chemical \\\: combination \: (bonding) \: to \: be \: possible, \\ there \: must \: exist\: an \: equilibrium \: between \: \\ the \: force \: of \: attraction \: and \: repulsion.[/tex]
Answer:
bonds are formed by joining atoms whether same or different elements to form molecules by uses of forces of attractions
PLEASE HELP FAST !!!
How should measurement of car 2 be taken to accurately measure the distance it travels? Be sure to include where the meter stick should be placed.
the experimental setup, with car 1 is at the top of a ramp and car 2 at the bottom of the ramp
car 1
/ ←top of ramp
/ ←bottom of ramp
car 2
answer
The meter stick should be placed at the starting position of car 2 at the base of the ramp so that it measures the part of car 2 that will end up the furthest away from the base of the ramp.
explanation
i dont know if this is right or not but my teacher gave me a 90 so there is a 50/50 chance its right or wrong