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:
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.
The rate of a chemical reaction can be found by measuring how ................. the reactants are ................. or how quickly the products are ...............
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!
calculate mass of MnO2 if 1 mole of KMnO4 completely burnt. 2KMnO4 -> K2MnO4+MnO2+O2
Answer: 80 grams
Explanation:
2KMnO4 -> K2MnO4+MnO2+O2
2 moles of KMnO4 would produce 1 mole of MnO2, so 1 mole of KMnO4 would produce 0.5 moles of MnO4. The molar mass of MnO4 is 160 g/mole. 1/2 mole of KMnO4 would therefore be (160 g/mole)*(0.5 moles) = 80 grams.
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
why does beryllium not liberate hydrogen from acid readily
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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9. SI base units used in chemistry include
A. kilograms, liters, inches, and moles.
B. pounds, gallons, moles, and Fahrenheit.
C. kilograms, seconds, moles, and Kelvin.
D. pounds, gallons, moles, and Celsius.
Answer:
C. kilograms, seconds, moles, and Kelvin
Plllsssss hel pls help
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.
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
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
Alkanes are chains of carbon atoms surrounded by hydrogen atoms. Which alkane has the weakest dispersion attractive force?
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 youIron has a density of 7.86 g/cm3. Calculate the volume (in dL) of a piece of iron having a mass of 4.59 kg .
How does the electronic configuration of an element give information about the period and the group it belongs to
Answer:
Electronic configuration of an element gives the information of valence electrons and number of shell present in the element.
Explanation:
Electronic configuration of an element gives the information of valence electrons and number of shell present in the element. We get the information of group number after knowing valence electrons.
The number of shells present in an element is equal to the period number. Thus, by knowing electronic configuration we know the group number and period number of an element, and the position of an element in the periodic table.
An element's electronic configuration, which identifies both its period and group, gives important details regarding its place within the periodic table.
The major energy level (shell) where the outermost electrons are found determines the period. In the electrical arrangement, the period number corresponds to the greatest energy level. The number of valence electrons, which are the electrons at the highest energy level, which are present in an element determines its group or family. Because they have the same valence electron configurations, elements in the same group exhibit comparable chemical characteristics. In conclusion, the electronic configuration helps us comprehend an element's chemical behavior and interactions with other elements by revealing an element's period based on energy levels and its group based on valence electrons.
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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?
Rain soaks into the soil or runs off into oceans, rivers, and lakes. ___________ which process is this
Answer:
The water falls to the earth as precipitation, such as rain, hail, sleet, and snow. When precipitation reaches the earth's surface, some of it will flow along the surface of the land and enter surface water like lakes, streams, and rivers, as runoff. The rest of it soaks or percolates into the soil, called
Element X forms the ion X22- What is the formula of the covalent compound X forms with chlorine?
A XCI
B XCl2
C XCl3
D XCl4
Answer:
the answer is mostly option a)XCl
Explanation:
Please help me answer this question
Answer:
d=m/v d=0.94
Explanation:
^^^^^^&&&&^^^^
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.
Determine the redox reaction represented by the following cell notation: Mg(s) | Mg2 (aq) || Cu2 (aq) | Cu(s)
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
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]
How many atoms are in 0.100 mol of C3H8
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.
What is the mass ratio for NH3?
Answer:
ratio by mass
14 3
mass ratio atomic mass
14/14 = 1 3/1=3
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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Enumerate seven commonly encounter functional group in organic compound
Answer:
-COOH
-CHO
-CO
-NH2
-X(-Cl, -Br, -I)
-RCOOR(R= Alkyl group)
-C6H5