1)How does the cut on your finger heal ? (1 mark )
2)Why is Rayon different from synthetic fibres? ( 1 mark )
3)What are synthetic fibres called? (1 mark )
4)Give examples which indicate that nylon fibres are very strong. (1 mark )
5) Explain why plastic containers are favoured for storing food . (3 marks )
6) Explain the difference between thermoplastic and thermosetting plastics. ( 3 marks)
Answer:
3) Some fibres are called synthetic because they are not made from natural fibres. Instead, they are made by chemical processing of petrochemicals. The synthetic fibres are made up of very large units called polymers. Some of the synthetic fibres are - nylon, rayon, acrylon
4) is used for making parachutes, rock climbing ropes, fishing nets, seat belts. A nylon thread is actually stronger than steel wire.
5) for the following reasons:
1. Plastic containers do not react with food
2. Plastic containers are light weight so they are easy to handle.
3. The price of plastic containers is very less as compared to other containers.
4. They have strong strength.
5.. Plastic containers are durable
6) (thermosetting plastic) have primary bonds between molecular chains and held together by strong cross-links
(Thermoplastics) have secondary bonds between molecular chains
A teacher demonstrates a chemical reaction. A student
observes that the test tube in which the reaction occurs
becomes warm. What is the source of the thermal
energy generated by the reaction?
Select one:
A. potential energy absorbed by the reaction
B. breaking bonds of the reactants
C. kinetic energy absorbed by the reaction
D. energy stored in the reactants
Answer: B, breaking bonds of the reactant.
Explanation:
This reaction is taking in energy and we know this because it says it 'becomes warm'.
Endothermic reactions take in heat/energy from the surroundings and bond breaking occurs during an endothermic reaction.
B. breaking bonds of the reactants which emits heat energy.
The test tube in which the reaction occur is warm because the heat energy is released due to the making of new bonds. When the new bonds are formed, energy is released in the form of heat.
Energy is needed to break bonds so it absorbed the bonds so we can say that bond-breaking is an endothermic process while on the other hand, energy is released when new bonds form so we can say that bond-making is an exothermic process.
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2) Which liberates the most energy?
A) F(g) + e ➡️ F-(g)
B) N(g) +e- ➡️ N-(g)
C) O(g) +e ➡️ O-(g)
D) C(g) +e ➡️ C-(g)
Answer: [tex]F(g)+e^-\rightarrow F^-(g)[/tex]
Explanation:
Electron gain enthalpy is defined as energy released on addition of electron to an isolated gaseous atom.
The amount of energy released will be maximum when the tendency to attract electrons is maximum. As flourine has atomic number of 9 and has electronic configuration of 2,7. It can readily gain 1 electron to attain stable noble gas configuration and hence liberates maximum energy.
[tex]F(g)+e^-\rightarrow F^-(g)[/tex]
what is the name of the compoud H2Co2
Mercury is a liquid at room temperature, gallium will melt if held in your hand, and aluminum is a solid that has a high melting point. All three are metals. How can you explain these observations using information about the strength of metallic bonds?
Answer:
the solid is so hard
Explanation:
yan na po sana makatulong po heheheh
Metals such as Gallium and mercury are different from that of other metals like aluminium because they are liquid at room temperature. This is because of valence electrons which are relatively free in these metals.
What are Metals?
All the metals except mercury and gallium are solids at room temperature. These metals are liquids because of both the high electrical conductivity and the thermal conductivity which come from the fact that one or more valence electrons is relatively free in these atoms to travel throughout the solid metal. This has been formalized in the Wiedemann-Franz law.
Both Gallium and mercury are unique elements (metals) which occur in the liquid state at near the room temperature. It is important here to note that mercury is essentially a liquid at room temperature while gallium becomes liquid at temperature near to room temperature. They both melt very easily due to the low melting temperature values.
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How cold is it on Uranus
Answer:
-371 degrees f
Explanation:
-371 degrees F.
speeds on Uranus range from 90 to 360 mph and the planet's average temperature is a frigid -353 degrees F. The coldest temperature found in Uranus' lower atmosphere so far is -371 degrees F., which rivals Neptune's frigid temperatures.
(hope this helps can i plz have brainlist :D hehe)
I gave brainlest:: answer this .....
Why does the periodic table have the shape it has
Answer: The arrangement of electrons in atoms is responsible for the shape of the periodic table.
Explanation: Electron configurations can be predicted by the position of an atom on the periodic table.
O_O O_O O_O
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The periodic table has the shape it has because the elements are arranged according to their atomic number, which is the number of protons in the nucleus of an atom.
The chemical elements are arranged in a periodic table in ascending order of atomic number, allowing one to observe trends in the elements' properties.
Here are some of the reasons why the periodic table has the shape it has:
The number of protons in the nucleus of an atom determines its chemical properties. Elements with similar numbers of protons have similar chemical properties, so they are grouped together in the periodic table.The number of electron shells in an atom determines its size and its reactivity. Elements with the same number of electron shells have similar sizes and reactivities, so they are grouped together in the periodic table.The number of valence electrons in an atom determines its chemical bonding. Elements with the same number of valence electrons have similar chemical bonding properties, so they are grouped together in the periodic table.The periodic table is a valuable tool for understanding the chemical properties of the elements.
Therefore, above mentioned are some of the reasons why periodic table has the shape it has.
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what are the elements of the liquids in the periodic table?
Answer:
bromine,mercury ,caesium,gallium,rubidium and francium
Explanation:
Answer:
Mercury
Bromine
Caesium
Rubidium
Francium
Gallium
These all are liquid elements
How many liters are in 100g of CoCl2?
Answer:
0.77018342688495
Explanation:
I did this
What kind of chemical reaction is H2SO4 + 2 KOH K2SO4 + 2 H2O
These are incorrect please put the right answer on the blanks\
for brainiest:)
Answer:
1. condensation
2. Temperature
3. evaporization
4. kinetic energy
5. sub limation
6. thermal energy
7. deposition
8. vaporization
which of the following choices are the characteristics of life
The diagrams below represent some respiratory structures in three organisms. The labeled structures in these organisms all have a similar function. What is the main function of the labeled structure(s) in each organism?
A)Circulation of blood
B)Digestion of food
C)Production of food
D)Exchange of gases
Answer:
D
Explanation:
Lungs, Moist skin , Gills is in the exchange of gases system
The correct answer is D.
The structure of human lungs is first demonstrated in an organism.
Lungs are the respiratory organs. They are made up of alveoli.Main Function :The main function of lungs is the gaseous exchange. This gaseous exchange occurs in the alveoli. Oxygen from atmosphere comes into the lungs through nostrils, nasal cavities, pharynx, larynx, trachea, bronchi and finally reaches the lungs. Then gaseous exchange occurs between blood and alveoli. Oxygen enters into the blood and carbon dioxide leaves the blood.The structure of Earthworms Moist skin is second demonstrated in an organism.
The earthworm has no special respiratory organs like lungs or gills. Respiration takes place through the body wall. The outer surface of the skin is richly supplied with blood capillaries which aid in the diffusion of gases. Oxygen diffuses through the skin into the blood while carbon dioxide from the blood diffuses out. The skin is kept moist by mucous and coelomic fluid and facilitates exchange of gases.The structure of Fish Gills is third demonstrated in an organism.
The gill filaments in fish have functions like lungs in people: it's the organ responsible for absorbing oxygen and expelling carbon dioxide. The gills also regulate levels of mineral ions and the pH of the blood, as well as being the primary site of nitrogenous waste excretion, in the form of ammonia.Learn more about Respiratory System here:
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what trend does the first ionization energy follow, going down the periodic table?
Answer:
going down the periodic table atomic size increases,electronegativity and ionization decreases going down
if 3 mol of fe2o3 reacts with 5 mol al what is the maximum amount of fe that was produced. Explanation please!
Answer:
Queso es yummy. If you give me below 5 stars u like sucking on rocks.
Explanation:
The following are steps in the process of cloning a mouse. Arrange the steps in the correct order. (8.L.2.1) *
1. Stimulate cell division. 2. Implant the embryo into the surrogate mother. 3. Isolate donor cells 4. Transfer genetic material from donor to egg cell.
A. 4-2-3-1
B. 3-4-1-2
C. 3-2-4-1
D. 1-3-4-2
Answer:
C
Explanation:
I got A wrong so maybe
When a chemical bond exists between two atoms, an electrical attraction exist between the __________ of each atom and the ___________ of the other atom no matter what type of bond you are talking about.
Answer:
c
Explanation:
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A 100.-gram sample of H2O(l) at 22.0°C absorbs 830. joules of heat. What will be the final temperature of the water?
Answer:23.976
Explanation:830j = 197.6 cal. 197.6/100g=1.976 degrees. plus 22 degrees =23.976
why ammonia is a identified as a weak base?
can you explain what it is meant by it only ionise partially?
Answer:
Ammonia doesn't contain any hydroxide ions to begin, but it's dissolved in water acquires hydrogen ion from the water to produce hydroxide as well as ammonium ions. However ammonia doesn't fully convert into hydroxide and ammonium ions in solution that's why ammonia is a weak base.
Plzzzzz helpppp meee
Answer:
2 and 5
Explanation:
How many moles are in 6.38x10^22 molecules/atoms of CO2?
Answer:
0.106 moles
Explanation:
To solve this problem we will need to use Avogadro's number, it is the number of molecules (or atoms) in one mol.
We convert molecules into moles using that number:
6.38x10²² molecules ÷ 6.023x10²³ molecules/mol = 0.106 moles
There are 0.106 moles in 6.38x10²² molecules of CO₂.
I need help ASAP!!!!! What happens to water when it changes to ice?
- It's density increases
- mass increases
- volume increases
Hope this helps!
Answer:
first one
Explanation:
what number repersents the subscript 5H2
Al+hcl=alcl3+H balance
Answer:
Explanation:
Kindly answer the way I have written.
help pleaseee
find the molecular formula of a compound with a molar mass of 70.0 g/mol and an empirical formula of CH2.
Answer:
In order to find the molecular formula from an empirical formula you must find the ratio of their molecular masses.
We know that the molecular mass of the molecule is 70
gmol-1
. We can calculate the molar mass of
CH2
from the periodic table:
C=12.01
gmol−1
H=1.01
gmol−1
CH2 =14.03
gmol−1
Hence we can find the ratio:
14.03
70
≈
0.2
PLEASE ANSWER ASSSSPAPPPP
Answer:
CH4 + 2O2 ----> 2H2O + CO2
PLS HELP DECODE THIS
The number of protons and neutrons are used to determine the:
(C1) T (H4) M (A1) C (H2) A (F4) S
Rock whose texture, mineralogy, or chemical
composition has been altered without melting it.
Answer:
I believe it would be C or B
Heat from the sun moves through space by the process of
es
A)
circulation.
B)
conduction
C)
convection.
D)
radiation