Answer:
1.25 x ( 6.02 × 10^23) = 7.525 × 10^23 atoms
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...
draw the atomic structure of 10 elements and show Electronic configuration.......
Answer:
ज
Explanation:
ूअूिkzkzkksksosawwhsusisisisisisiisisisisisisiisisisis
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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What are the products of combining iron (II) and Copper (II) oxide in a Chemical reaction?
oxide in a chemical reaction
CuFe2O4 are the products of combining iron (II) and Copper (II) oxide in a Chemical reaction.
What is chemical reaction?The conversion of one or more chemicals into new one or more chemicals is called chemical reaction.
Example: iron reacts with oxygen to form rust.
What is product?The final substance of chemical reaction is called product.
Example: CuFe2O4 is the final substance called product when iron (II) and Copper (II) oxide react with each other.
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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
Some groups have names. Enter the number-letter version of the group number for each of these named groups. Be sure to include the number and letter.
a) Alkali metals:
b) Alkaline earth metals
c) Halogens
d) Noble gases 8.
The groups are alkali metals (I), alkaline earth metal (II) , Halogen (VII), and noble gases (VIII).
What is group?The representative elements, also known as the primary group elements, are found in Group A. As a result, the columns beginning with A (IA through VIIIA) are referred to as the primary group elements. The periodic table's columns were referred to as groups.
Alkali metals belongs to group (I).Alkaline earth metals belongs to group (II).Halogens belongs to group (VII).Noble gases belongs to group (VIII)To know more about group.
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An organized method scientists use to solve problems and test
hypotheses
hypothesis
scientific process
conclusion
experiment
Explanation:
Hypothesis is answer.
Have a great day
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
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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What is the Ka expression for HCO3 ?
If you wanted to increase the speed of
vaporization, you could
A. put the substance in the freezer.
B. place a lid on the substance.
C. heat the substance to the boiling point.
D. cool the substance to the freezing point.
>
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Answer:
C. heat the substance to the boiling point.
Answer:
heat the substance
Explanation:
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.
If the PH is 5.85.how do I calculate for an acid ?[H^+]
Answer:
if its under 7 then it's an acid you neek over 7 is alkaline
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 the systematic name of the following compound?
Li2S
Choose 1 answer:
А
Lithium sulfate
B В
Lithium sulfide
Dilithium sulfate
Dilithium sulfide
Explanation:
Lithium sulfide
if my answer helps you than mark me as brainliest.
What is the specific heat of a metal with a mass of 14.0 g, heat of 3.45 kJ and a change in temperature of 6.2 ?
Answer:
Explanation:
0.0
7. Which of the following is not part of the proper protocol for using acids and bases?
A. Wearing protective clothing while handling
B. Storing acids and bases below 10°C
O C. Storing acids and bases in separate areas
D. Add acid to water, not water to acid
Answer:
D. Add acid to water, not water to acid
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:
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
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:
I want the solve of this problem
Answer:
the answer of this question is B
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.
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
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.
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
Which of the following is the correct net ionic equation for the formation of barium sulfate?
O B2+(aq) + SO42- (aq) → BaSO4 (s)
Ba2+(aq) + S2(aq) → Bas(s)
Be2+ (aq) + S042(aq) → BeSO4 (5)
Ba2+(aq) + SO42 (aq) → BaSO4 (5)
Answer:
Ba²+ (aq) + SO4²- (aq) --> BaSO4(s)
The net ionic equation for the formation of barium sulphate is Ba²⁺₍aq₎ + SO₄² ₍aq₎ → BaSO₄₍s₎. Therefore, option D is correct.
What is barium sulphate ?The inorganic substance having the chemical formula BaSO₄ is called barium sulfate. It is a tasteless, crystalline white substance that is insoluble in water. The main commercial source of barium and the materials made from it is the mineral barite, which is where it naturally occurs.
The use of barium sulfate aids in the diagnosis or discovery of issues with the esophagus, stomach, and bowels. It is a contrast material for radiography. To make the various bodily components clearly visible, contrast chemicals are used.
A barite-derived metallic compound with a silvery white color. In barium swallows and barium enemas, it is diluted with water to aid visualize the digestive tract on an x-ray.
Thus, option D is correct.
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Is NaClO4/HClO4 a buffer system
Answer:
In this type of solution, perchloric acid is a strong acid which means that its conjugate base is extremely weak. As such, the solution of HClO4 H C l O 4 and NaClO4 N a C l O 4 is not a buffer solution.
Ammonia is produced by the reaction of nitrogen and hydrogen according to the equation
N2(g) + 3H2(g) → 2NH3(g)
Calculate the mass of ammonia produced when 27.0 g of nitrogen react with 12.0 g of hydrogen.
g NH3
Which is the excess reactant and how much of it will be left over when the reaction is complete?
Explanation:
Ammonia is produced by the reaction of nitrogen and hydrogen according to the equation
N2(g) + 3H2(g) → 2NH3(g)
Calculate the mass of ammonia produced when 27.0 g of nitrogen react with 12.0 g of hydrogen.
g NH3
Which is the excess reactant and how much of it will be left over when the reaction is complete?
What kinds of questions cannot be answered by chemistry
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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