Where did you put H an He? What are your reasoning for placement?
Answer:
On the placement of hydrogen and helium in the periodic system
H1=1
He2=2
D
Question 3
1 pts
In olden times, apothecaries used to dispense medicine using their own system of measurements
that are listed below. Use these conversions to determine how many milligrams would be in a
sample of 1.250 scruples.
1 apothecary pound = 12 ounces
1 ounce = 8 drams
3 scruples = 1 dram
1.2153 apothecary pound = 1 English pound
1 kg = 2.205 English pounds
Enter your answer to the correct number of significant digits. Do not include the units.
Changing 1.250 scruples to milligrams.
To convert from a unit to another, First write the conversion guide
then cross multiply in such a way that the unit both top and bottom
cancel out each other together with dividing or multiplying the values associated with them.
To get to the answer we have to wor it out step by step.
First step
3 scruples = 1 dram
1.250 scruples=
= [tex]\frac{1.250 scruples x 1 dram}{3scruples}[/tex] = 0.41667dram
2nd step
8 drams=1 ounce
0.41667drams =
[tex]\frac{0.41667drams x 1}{8 drams }[/tex] =0.05208 ounces
3rd step
1 apothecary pound = 12 ounces
?apothecary pound =0.05208 ounces
[tex]\frac{0.05208 ounces x 1apothecary pound }{12 ounces}[/tex] =0.00434 apothecary pound
4th step
1.2153 apothecary pound = 1 English pound
0.00434 apothecary pound =
[tex]\frac{0.00434 apothecary pound x 1 English pound}{1.2153 apothecary pound }[/tex]
==0.003571 English pound
5th step
1 kg = 2.205 English pounds
??kg =0.003571 English pound
[tex]\frac{0.003571 English pound x 1kg }{2.205 English pounds}[/tex]
=0.00161950kg
6th step
1kg =0.00161950kg
0.00161950kg=
[tex]\frac{0.00161950kg x 0.00161950kg}{1kg}[/tex]
=1,619.50mg
Therefore, 1.250 scruples=1,619.50mg
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I need help please Which is the proper conversion factor for converting a mass expressed in pounds (lb) to the same mass expressed in grams (g)?
Answer:
C
Explanation:
There are roughly 454 grams for every pound. The conversion factor would look like this for converting 2 lbs of a sample into grams:
2lbs sample (454g sample/1lb sample) = sample in grams.
The rate of a chemical reaction can be found by measuring how ................. the reactants are ................. or how quickly the products are ...............
Salt water has a density of 1.183g/mL. A ball has a density of 0.0134 g/mL. Will the ball float or sink?
Enumerate seven commonly encounter functional group in organic compound
Answer:
-COOH
-CHO
-CO
-NH2
-X(-Cl, -Br, -I)
-RCOOR(R= Alkyl group)
-C6H5
Please help me answer this question
Answer:
d=m/v d=0.94
Explanation:
^^^^^^&&&&^^^^
why does beryllium not liberate hydrogen from acid readily
Plllsssss hel pls help
True or False
Matter is the ability to do work or cause change.
False is the correct answer.
Answer:
False
Explanation:
It is Energy that has the ability to cause change.
An atom has 30 protons and 30 neutrons. What is its mass number?
Mass number=No of protons+No of neutrons
[tex]\\ \sf\longmapsto Mass\:No=30+30[/tex]
[tex]\\ \sf\longmapsto Mass\:No=60[/tex]
Explanation:
Here,
Protons(p+)=30
Neutrons(N⁰)=30
We know,
Atomic mass(z)=(P+)+(N⁰)
=30+30
=60
what is stoichiometry?
Answer:
the relationship between the relative quantities of substances taking part in a reaction or forming a compound, typically a ratio of whole integers.
Explanation:
G o o g l e
Explanation:
Stoichiometry is the calculation of reactants and products in chemical reactions in chemistry.
A scientist observed that tobacco plants flower only at certain times of the year. After careful consideration of this phenomenon, the scientist conducted an experiment. She grew five tobacco plants and exposed each to light for a specific period of time each day. Study the diagrams below which show the results of this experiment. Then complete the sentences that follow.
1. Since only one variable was changed in this experiment, this is called a
experiment.
2. The independent variable in this experiment is .
3. The dependent variable in this experiment is .
4. List some of the controlled variables in the experiment. (Identify at least three.)
An experiment is performed to study how the change in some variables affects other related variables.
I can't see the diagrams but I can give you general answers for each statement.
1) We define a good experiment as an experiment where only one variable is tested at the time, this is because this allows the scientists to isolate the impact of that variable in the experiment.
"Since only one variable was changed in this experiment, this is called a good experiment."
2) The independent variable is the variable that the scientists can change in an experiment, in this case, we know that she does change the hours of light that each plant gets, so we can conclude that the independent variable is the time of light exposition that each plant gets.
"The independent variable in this experiment is the time of light exposition"
3) The dependent variable in an experiment is the variable that reacts to the changes in the independent variable, it usually is the thing that the scientist wants to study. In this case, we know that she is studying the floration times of tobacco plants, so:
"The dependent variable in this experiment is the flowering time of tobacco plants"
4) Controlled variables are, in principle, independent variables, that are fixed for the whole experiment. We can't see the controlled variables because there are no graphs, but we can think about what we should fix in this type of experiment.
The temperature: All the plants should grow in the same temperature, as it can affect the flowering times.
The humidity: The humidity also could impact on the flowering of the plants, so we need to fix it for the 5 plants.
The strain: All 5 tobacco plants need to be from the same genetics, we know that different genetics from different parts of the world may react differently to changes in light or temperature, so the strains need to be equal.
Substrates: All the plants should be on the same substrate, so she can be sure that all the plants are getting exactly the same nutrients from the soil.
These are just some examples, if you were designing this experiment, you would see that there are a lot of variables that need to be controlled.
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Ceramics make excellent refractory materials. A material is said to be refractory if it:
1 has high refractive index
2 retains its strength at high temperatures
3 resists the flow of electric current 4 all of the mentioned
Answer:
Option 2 is the correct answer
Explanation:
Ceramics, which mainly consist of oxides, carbides and nitrides, can withstand very high temperatures; furnaces are generally lined with such ceramics.
Doping Se with P would produce a(n) ________ semiconductor with ____________ conductivity compared to pure Se.
Use VSEPR Theory to predict the molecular geometry around the central atom in each of the following molecules. Which of the following molecular geometries are correct?
1. XeF4, square planar
2. ICI., tetrahedral
3. SF4, seesaw
a. 1 and 2
b. 3 only
c. 1 and 3
d. 2 only
e. 1, 2 and 3
Polymers are long chains of:
A. crystals.
B. molecules.
C. simple molecules
D. atoms
Answer:
The answer should be Molecules.
Explanation:
Polymers are said to be synthetic or natural substances that are formed by joining the monomeric units together by bonds. They are long chains of molecules. Thus, option B is correct.
What are polymers?Polymers are macromolecules that are large and big in size that is composed of multiple chemical units of various molecules linked by chemical bonds. These substances can be natural or man-made.
The polymers are composed of monomeric units that are molecules like the starch polymer made of glucose monomeric units linked by the glycosidic linkages. They are complex and tough structures that often provide structural support and protection.
Proteins, carbohydrates, lipids, and nucleotides are polymers composed of amino acids, sugar, fatty acids, and nucleic acids. Polymers are involved in various functions in living organisms.
Therefore, option B. molecules make long chains of polymers.
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What are precautions to be taken when doing titrations? A-Make sure to always vigorously shake that flask after every drop if the end point is still unknown. It may be that the remaining volume of the titrant needed to reach the end point is just adhering on the wall. This is to ensure accuracy. B-The amounts of solid and liquid should be weighed and pipetted with high accurac This is because all the data that will be produced will mainly depend on this. C- If the end point is unknown, dropwise addition of the titrant is recommended. D- Always make sure that the indicator is added. E- All of the above
Answer:
E
Explanation:
This is because all steps from A-D are important to obtain an accurate result
The SARS-Cov2 spike protein has a large N-terminal domain, a transmembrane helix and a short C-terminal region. Before the structure of the protein was known, researchers analysed its amino acid sequence using hydropathy plot analysis to predict the position of loops exposed to an aqueous environment because these show as:
A broad peak (>20 residues) of mixed positive and negative hydropathy
A broad peak (>20 residues) of positive hydropathy
A narrow (5-10 residues) of positive hydropathy
A narrow peak (5-10 residues) of negative hydropathy
Answer:
Explanation:
-g
How many atoms are in 0.100 mol of C3H8
how much energy is contained in 3moles of chlorine
Answer:
1 mol of cl2 contains 71 g
3 mol of cl2 will contain÷
3×71=213 g
Explanation:
There ;3
Answer:
213 g
Explanation:
multiply 3 moles by relative atomic mass of chlorine which is 35.45×2 because its two chlorines and your answer will be 213g
In what state of matter is carbon dioxide normally found on Earth?
Answer:
Gas
Explanation:
I believe that it is usually a gas on Earth.
Write electronic configuration of Na and Ca on the basis of subshell.
Na:-
Sodium has 11 electrons so the EC followed by
[tex]\\ \sf\Rrightarrow 1s^22s^22p^63s^1[/tex]
Ca:-
Calcium has 20electrons so the EC followed by
[tex]\\ \sf\Rrightarrow 1s^22s^22p^63s^23p^63d^2[/tex]
6.3 gram of HNO3 as mass of nitrate
Moles of HNO 3
= 6.3/63 = 0.1 moles
HNO3 has 1 atom of H , 1 atom of N , 3 atoms of O
No of atoms = moles of molecule × atomicity of atom × avogadro number
No of atoms of H =0.1×1×6.023×10^23
= 6.023×10^22
No of atoms of N =0.1×1×6.023×10^23
= 6.023×10 ^22
No of atoms of O =0.1×3×6.023×10 ^23
= 18.069×10 ^22
Which family of metals is the most reactive?
Rare Earth metals
Transition metals
Alkaline Earth metals
Alkali metals?
Answer:
Alkali metals
Explanation:
Hope you like my answer and my answer helped youDetermine the redox reaction represented by the following cell notation: Mg(s) | Mg2 (aq) || Cu2 (aq) | Cu(s)
What is the mass ratio for NH3?
Answer:
ratio by mass
14 3
mass ratio atomic mass
14/14 = 1 3/1=3
What is the oxygen tank and equipment used for and how is it used??
Answer:
Oxygen tanks are used to store gas for: medical breathing at medical facilities and at home. breathing at altitude in aviation, either in a decompression emergency, or constantly (as in unpressurized aircraft) oxygen first aid kits.
Explanation:
Mark my answer as the brainliest!
The orbit of a planet is an ellipse with the sunat one of the foci.. This is Kepler's........ second law third law first law
Answer:
its keplers first law
Explanation:
answer from gauth math
What are your main fears about this class (if any)?
Answer:
sitting n front of class
reading out loud
and being stressed
and being bullied
Explanation: