Propose routes to the following compounds from propyl bromide and any necessary organic or inorganic reagents:
a. propyllithium
b. propylmagnesium bromide
c. propylzinc bromide
d. Dipropylzinc
Am element has 18 electrons ,20 neutrons and a charge of -2.what is the mass number?..a.38 b.40 c.32 d.39
Answer:
Surely you must have a Periodic Table beside you....?
a=38
Explanation:
You gots Z=18, the atomic number, where Z is the number of nuclear protons. The number of protons defines the element....and thus we got calcium....
....and with 20 neutrons we got the 38Ca isotope....the which is rather short-lived...
What kinds of questions cannot be answered by chemistry
A cation of 2 indicates that an element has Group of answer choices lost two neutrons. lost two protons. gained two electrons. lost two electrons. gained two protons.
Answer:
lost 2 electrons
Explanation:
A cation by definition is a positively charged ion. They are formed when a metal loses its electrons. A cation has more protons than electrons, giving it a net positive charge. So, it had to have lost 2 electrons to give it a positive charge of 2⁺.
What is Displacement reaction . Explain with an example.
Explanation:
A displacement reaction is the one wherein the atom or a set of atoms is displaced by another atom in a molecule. For instance, when iron is added to a copper sulphate solution, it displaces the copper metal. A + B-C → A-C + B.
45. Show that the acceleration of a hamster is 5 m/s2 when it
increases its velocity from rest to 10 m/s in 2 s.
The acceleration of the hamster is 5 m/s².
Acceleration is the rate of change of velocity per unit of time.
Given:
Initial velocity (v₀): 0 m/s (rest)Final velocity (v): 10 m/sTime elapsed (t): 2 sWe can calculate the acceleration of the hamster using the following expression:
[tex]a = \frac{v-v_0}{t} =\frac{10m/s-0m/s}{2s} = 5 m/s^{2}[/tex]
The acceleration of the hamster is 5 m/s².
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What is the correct clases for this drugs
Promethazine
heelp me please
Answer:
MedlinePlus Drugs Information
Explanation:
Promethazine is in a class of medication called phenothiazines
solve for x . 4x-300=-8×
Answer:
4x+8x=30
12x=300
x=300/12
x=25
A student wants to do a scientific research on how a nuclear fusion can be used as a power source on earth. What type of scientist does the student want to become?
A nuclear scientist because they are more focused on extracting the nuclear energy of atoms.
Ganciclovir is used to treat cytomegalovirus, a deadly viral infection common in immunocompromised patients. The doctor places an order for a dose of 2.5 mg/kg of body weight. What dose will the nurse administer for a 141 lb patient?
A. 160 mg
B. 56.4 mg
C. 352 mg
D. 124 mg
Answer:
A.160mgs
Explanation:
First you convert the lbs to kgs, 141lbs=63.957kgs
then you divide 63.957kgs by 2.5 which is 159.89
round up to 160, 160mgs is the correct dosage.
The dose that will the nurse administers for a 141 lb patient is 160mgs. The correct option is A.
What is a virus?
A virus is an entity that is only become alive when it gets a living host. It takes survives in its host and affects the body of the host. They are microorganisms that can not be seen by direct eyes. Viruses are harmful microorganisms. They are very deadly and they transmit through breath.
Medication, contain treatment that includes drugs and therapies to recover the patient from the disease. It is a proper process that includes timely procedures.
First, you convert the lbs to kgs, 141lbs = 63.957kgs
Then you divide 63.957 kgs by 2.5 which is 159.89 round up to 160, 160mgs is the correct dosage.
Thus, the correct option is A. 160 mg.
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Water
(liquid)
Pressure (atm)
1
05-
025-
Ice
( (solid)
Water vapor
(gas)
10
101
100
Temperature (°C)
What do the sections between the lines on a phase diagram represent?
A. The regions in which temperature and pressure change a
substance's phase
B. The conditions in which a substance exists in a certain phase
C. The ranges where temperature and pressure are constant in a
substance
D. The areas in which the kinetic energy of a substance is constant
Answer:A
Explanation:
1.List three (3) importance of photosynthesis to our ecosystem. a) b) c)
Answer:
It is the number one source of oxygen in the atmosphere. It contributes to the carbon cycle between the earth, the oceans, plants and animals. It contributes to the symbiotic relationship between plants, humans and animals. It directly or indirectly affects most life on Earth
Answer:
three importance are
it helps in fixing and balancing the amount of carbon dioxide and oxygen in the atmosphere
it provides the nutrition to the plant
it helps the. plant in its growth
I can distunguish between elements, compounds and mixtures.
3.1 I can describe what elements anre and give examples of them.
3.2 I can describe what mixtures are and give examples of them.
3.3 I can describe what compounds are and give examples of them.
0 0
This picture represents..
O a compound
O an element
O a mixture of elements
O a mixture of compounds
Answer:
an element
Explanation:
that is the answer yep
it represent an element
Name
maddison, M
Date
Vocabulary
Write the word next to the description it matches.
mixture
solubility
solution
1.
2.
the degree to which a material will dissolve in another
substance
different materials placed together but keeping their own
properties
a mixture in which substances are spread out evenly and
will not settle
3.
Okay
Answer:
solubility- the degree to which a material will dissolve in another substance
mixture- different materials placed together but keeping their own properties
solution- a mixture in which substances are spread out evenly and will not settle
Which list only includes terms that describe oxygen gas, O2?
A. element, molecule, pure substance
B. atom, compound, molecule
C. atom, element, molecule
D. compound, molecule, pure substance
Answer:
d
Explanation:
it just makes alot of sense and you got this
Oxygen is a gas that belongs to the chalcogen family and is a reactive non-metal. It is an element, molecule, or pure substance. Thus, option A is correct.
What is a pure substance?A pure substance is defined as a substance that cannot be physically separated into its constituent particles. They are known to have a definite and constant chemical composition. It can be a molecule, element, or compound.
An element is atomic species that cannot be broken into simple sub-particles by chemical processes. On the other hand, if an atomic element bonds to the same or different atom it forms a molecule.
Oxygen gas is an element composed of two atoms of oxygen and is a molecule as the two atoms are linked chemically. It is also a pure substance as it contains the same element.
Therefore, option A. oxygen gas is a pure substance, an element, and a molecule.
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Bio-Clemical reactions talking Place in every Cell organelles
Answer:
Each of these organelles performs a specific function critical to the cell's survival. For example, biochemical reactions in a cell's mitochondria transfer energy from fatty acids and pyruvate molecules into an energy-rich molecule called adenosine triphosphate (ATP).
Explanation:
Class 8 chemistry : metals and non metals describe the process of formation of coal in the nature
Explanation:
Coal is formed when dead plantand animals matter decays into peat and is converted into coal by the heat and pressure of deep burial over millions of years.
What was the variable that Sunil changed in his experiment?
Explanation:
The things that are changing in an experiment called variables. A variables is any factor , trail , or condition that can exist in differing amounts or types. The independent variables is the one that is changed by the scientist. Why just one? well, if you changed more than one variables it would be hard to fight out which be hard to fight out which change is causing what you observe . For example, what if our scientists question was:" how does the size of a dag affect how much ismts eats?" then, during your feeding experiment you changed both the size of the dog and the time of day the dags were fed.
What is the Ka expression for HCO3 ?
What kinds of evidence might be used to conclude that you have isolated a new element?
The evidence that might be used to conclude that I have isolated a new element is the number of protons in the nucleus.
Chemical elements are different materials that have been found in nature that are characterized by having chemical characteristics different from other elements.
One way to know if I have found and isolated a new element is by showing that it does not have the same number of protons in the nucleus because this is what defines the characteristics of each element and each one has a different number of protons in the nucleus.
Therefore, the first thing I must do when I think I have found a new element is to isolate one of its atoms and check that it does not have the same number of protons in the nucleus as another element.
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A container with a specific volume “V” changes to “2V”. What happens to the average distance between gas molecules? Assume that pressure and temperature of the gas remain constant.
How mant grams are there in 7.15 x 10^24 molecules of water?
A)11.88g
B)214.02g
C)0.66g
D) 1.29 x 10^26g
E)3.97 x 10^23 g
Answer:
B. 214.02
Explanation:
1 mol of water weighs 18.015 gm and contains 6.023 × 10²³ molecules
From question, We have 7.15 × 10²⁴ molecules
Dividing we get (7.15 × 10 ²⁴) ÷ ( 6.023 × 10²³) = 11.871 molecules
Now, Weight of water = 11.871 × 18.015 = 213.85 which is nearer to option B
Answer:
[tex]\boxed {\boxed {\sf B. \ 214 \ g }}[/tex]
Explanation:
We are asked to find the mass of a given number of water (H₂O) molecules.
1. Convert Molecules to MolesFirst, we convert molecules to moles. We will use Avogadro's Number or 6.022 × 10²³. This is the number of particles (atoms, molecules, formula units, etc.) in 1 mole of a substance. In this case, the particles are molecules of water. Therefore, there are 6.022 ×10²³ molecules of water in 1 mole of water.
We will convert using dimensional analysis, so we must set up a ratio using the underlined information.
[tex]\frac {6.022 \times 10^{23} \ molecules \ H_2O}{1 \ mol \ H_2O}[/tex]
We are converting 7.15 × 10²⁴ molecules of water to moles, so we multiply the ratio by that value.
[tex]7.15 \times 10^{24} \ molecules \ H_2O*\frac {6.022 \times 10^{23} \ molecules \ H_2O}{1 \ mol \ H_2O}[/tex]
Flip the ratio so the units of molecules of water cancel each other out.
[tex]7.15 \times 10^{24} \ molecules \ H_2O*\frac {1 \ mol \ H_2O} {6.022 \times 10^{23} \ molecules \ H_2O}[/tex]
[tex]7.15 \times 10^{24} *\frac {1 \ mol \ H_2O} {6.022 \times 10^{23} }[/tex]
[tex]\frac {7.15 \times 10^{24}} {6.022 \times 10^{23} } \ mol \ H_2O[/tex]
[tex]11.87313185\ mol \ H_2O[/tex]
2. Convert Moles to GramsNext, we convert moles to grams. We will use the molar mass. This is the mass of 1 mole of a substance. These values are found on the Periodic Table. They are equivalent to the atomic masses, but the units are grams per mole instead of atomic mass units.
Look up the molar masses of the individual elements in water: hydrogen and oxygen.
H: 1.008 g/mol O: 15.999 g/molThere is a subscript of 2 after H, so there 2 moles of hydrogen in 1 mole of water. Multiply the molar mass by 2 before adding oxygen's molar mass.
H₂: 1.008 * 2 = 2.016 g/mol H₂O: 2.016 + 15.999 = 18.015 g/molWe convert using dimensional analysis again and set up another ratio.
[tex]\frac {18.015 \ g \ H_2O}{ 1 \ mol \ H_2O}[/tex]
Multiply by the number of moles we just calculated.
[tex]11.87313185 \ mol \ H_2O *\frac {18.015 \ g \ H_2O}{ 1 \ mol \ H_2O}[/tex]
The units of moles of water cancel.
[tex]11.87313185 *\frac {18.015 \ g \ H_2O}{ 1 }[/tex]
[tex]213.8944703 \ g \ H_2O[/tex]
The original measurement of molecules has 3 significant figures, so our answer must have the same. For the number we found, that is the one place. The 8 in the tenths place tells us to round the 3 up to a 4.
[tex]214 \ g \ H_2O[/tex]
There are approximately 214 grams of water and choice B is correct.
Things around you. All around you there is matter. The chair you are sitting on, air and
water are all matter. Almost everything that you see is matter. Anything that has mass
and takes up space is called matter.
What do we call something that has mass and takes up space?
Answer:
Hi Lovelys!!
Answers down below!!
Explanation:
There are two answer my me: Matter and Volume
Matter is anything that has mass and takes up space. Mass gives an object the property of weight and inertia (resistance to change in the motion of an object).
Volume simply refers to the space an object takes up. Depending on the physical state of an object, there are a couple ways to measure volume. If we are trying to measure the volume of a box, for instance, we would multiply the length of the box by its height and by its width.
Hope this helps!! =3
Have a wonderful day, evening, or night!! <3
What's the electron configuration of an N-3 ion?
A) [H]
B) [Ne]
C) [He]
D) [Ar]
Answer:
C) [He]
Explanation:
Answer:
B) Ne
Explanation:
took the test
Draw the keto and enol forms of 3,3-dimethylbutan-2-one, circle the more stable tautomer, and propose a mechanism for the conversion of one tautomer to the other in acidic conditions.
Please help thank you (15 points)
Answer:
Jupiter.
Explanation:
Jupiter has the fastest axial rotation time (day) in the list of answers, based on the fact that its day is only 10 hours long.
The specific gravity of a vegetable oil is 0.92. What is the massgrams, of 330 mL of vegetable oil?
Answer:
HOPE THIS ANSWER WILL HELP YOU
a 2.00 mL sample of a substance A has a density of 18.4g/mL and a 5.00 mL sample of substance B has a density of 35.5g/mL. do you have an equal mass of substances A and b?
this question made my brain hurt. please explain :(
Answer:
no
Explanation:
make use of this formula to find the mass of each sample.
m=density*volume
Oceanography does not include the study of which of the following topics?
A.the relationship between the Sun, Moon, and Earth
B.the relationship between the atmosphere, Earth, and the oceans
C.the Earth's oceans
D.the plants and animals that live in the oceans
Answer:
A. The relationship between the Sun,Moon,and Earth
Explanation:
4. In KCl, how are the valence electrons distributed?
O A. The electrons are shared between many K and Cl ions, creating a "sea of electrons."
B. The electrons are transferred from K to CI.
O c. The electrons are equally shared between K and Cl, forming a covalent bond.
D. The electrons are unequally shared between K and Cl, forming a polar covalent bond.
Answer:
Since KCl is an ionic compound, there is transfer of electrons from K to Cl. Thus right answer should be (B)
KCl is a chemical called potassium chloride that has been known to be an ionic compound. The valence electrons ion KCl gets transferred from K to Cl ion. Thus, option B is correct.
What is an ionic bond?An ionic bond is said to be a type of chemical bond that involves the gain and loss of the electron in the valence shell of the atom species. It involves the bond formation between the ions.
The ions with opposite charges, carrying a positive and negative are said to bond by accepting and donating their electrons to achieve the noble-gas (electronic) configuration.
In KCl, potassium has more electrons and can donate it to chlorine species as the latter lacks electrons. Chlorine accepts electrons and in the process acquires a negative charge, whereas potassium gains a positive charge.
Therefore, option B. the KCl involves ionic bonds by transferring electrons.
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