What is Aerosol,sol and gel
The transition metals (with the exception of Zn, Cd and Hg) are very much hard and have low volatility. Why Zn ,Cd and Hg has low melting points. (a) These have all their electrons paired. (b) These have maximum number of unpaired electrons. (c) These have very strong metallic bonding. (d) These have more metal-metal bonding.
Answer:
Zn ,Cd and Hg has low melting points because - These have all their electrons paired.
Explanation:
These have all their electrons paired -: All the electrons in the d-subshell are combined with Zn , Cd and Hg. The metallic bonds present in them are, therefore, weak. This is why they have low points of melting and bolting. therefore , this statement is true. These have maximum number of unpaired electrons. Since , these transition metals have all electrons paired , so this statement is incorrect.These have very strong metallic bonding -: Zn, Cd and Hg d-orbital are completely filled. They have poor metallic bonding and less compact packing due to their fully filled d-orbitals, so all of them are volatile in nature. Therefore, this statement is also not valid .These have more metal-metal bonding. -: Since , their metallic bond is weak , so this statement is not true .Hence , the correct option is A (These have all their electrons paired).
An unknown substance has a volume of 2 cm3 and a mass of 38.6 grams.
What is the density of the sample?
Answer:
The answer is 19.3 g/cm³Explanation:
The density of a substance can be found by using the formula
[tex]density = \frac{mass}{volume} \\ [/tex]
From the question we have
[tex]density = \frac{38.6}{2} \\ [/tex]
We have the final answer as
19.3 g/cm³Hope this helps you
Jack has a rock.the rock has a mass of 14g and a volume of 2cm^3.what is the density of the rock?
1
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Answer:
7
⋅
g
⋅
c
m
−
3
Explanation:
Molecules in a liquid are:
closer together than in a gas
moving more quickly than in a solid
moving more slowly than in a gas
all of the above
Please help!!!
Answer:
all of the above
Explanation:
Which of these statements describes a chemical property?
Answer:
it rusts when exposed to air
Answer:
A
Explanation:
What are natural resources
Answer:
resources that come from the ground or eath naturally which also means that those minerals like coal take hundreds of years to be created
what is the journey around the sun by earth called, and how long does it take?
Answer:
Its called ecliptic and it takes 365 days
Explanation:
Answer:
The journey around the Sun by Earth is called a revolution, it takes 365-and-a-quarter-days.
Explanation:
An object with a mass of 1.2 g takes up a space of 2.4 mL. What is it's density?
Answer:
The answer is 0.5 g/mLExplanation:
The density of a substance can be found by using the formula
[tex]density = \frac{mass}{volume} \\ [/tex]
From the question we have
[tex]density = \frac{1.2}{2.4} \\ [/tex]
We have the final answer as
0.5 g/mL.Hope this helps you
Which of the following is NOT an example of a chemical change? *
O Corrosion
O Grinding
O Combustion
O Rust
Help pleaI’ll give brainliest
Which element has the
greatest number of valence electrons available for bonding?
O selenium
Oboron
O calcium
O chlorine
Please can I have help on these two questions I’ll be very grateful!!!!!!
Answer:
-1 IS THE CHARGE OF ELECTRON AS THEY ARE NEGATIVE
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Why are small quantities of chlorofluorocarbons so harmful to the ozone layer? a. The chlorofluorocarbons act like ultraviolet radiation causing large amount of ozone to be produced. b. The chlorine from the chlorofluorocarbons reacts with free molecules of oxygen causing a stop in ozone production. c. Free oxygen atoms can replace the chlorine in chlorine monoxide, releasing a free atom of chlorine which can then recombine with an oxygen atom in ozone, destroying more ozone. d. Chlorofluorocarbons absorb ultraviolet radiation, preventing the formation of ozone.
Answer:
Why are small quantities of chlorofluorocarbons so harmful to the ozone layer? Free oxygen atoms can replace the chlorine in chlorine monoxide, releasing a free atom of chlorine which can then recombine with an oxygen atom in ozone, destroying more ozone.
Explanation:
The statement for small quantities of chlorofluorocarbons so harmful to the ozone layer is "Free oxygen atoms can replace the chlorine in chlorine monoxide, releasing a free atom of chlorine which can then recombine with an oxygen atom in ozone, destroying more ozone."
What is ozone layer?The ozone layer is a thin layer of air in the Earth's atmosphere that absorbs nearly all of the sun's damaging UV radiation.
What is CFCs?CFCs (chlorofluorocarbons) are harmless and nonflammable compounds made up of carbon, chlorine, and fluorine atoms.
The earth's protective ozone layer is destroyed by chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs), and halons, which shield the earth from damaging ultraviolet (UV-B) rays released by the sun. CFCs and HCFCs also warm the earth's lower atmosphere, causing global climate change.
When some substances are exposed to high UV radiation in the stratosphere, they emit chlorine or bromine. Ozone-depleting chemicals are compounds that contribute to ozone depletion (ODS). Chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs), carbon tetrachloride, and methyl chloroform are examples of ODS that produce chlorine. Halons and methyl bromide are two ODS that emit bromine.
Because there isn't much ozone in the atmosphere, what little there is is critical for protecting the Earth's surface from excessive UV light from the Sun. It turns out that it reacts with chlorine, which means that chlorine effectively eliminates ozone.
When the chlorine in CFCs combines with ultraviolet light, it releases chlorine, which then reacts with ozone, reducing the protection humans get from ultraviolet light, allowing more CFCs to release chlorine, and so on. Multiple ozone molecules will interact with one free chlorine atom, which is free because UV light has hit the CFC molecule. As a result, the damage it can cause is likely to be significantly more than you might imagine.
Hence the correct option is c.
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A physical change is easier / more difficult to reverse than a chemical change.
Answer:
the answer is that a physical change is easier to reverse then a chemical change.
Explanation: In order for a physical change to take place it's easier to just undo what happened then if it was a chemical change because in order for very few chemical changes to reverse to it's original substance you would need another chemical change.
What is the significance of an electronegativity difference of 1.7 between 2
atoms?
O A. It tells which atoms form positive ions and which atoms form
negative ions.
OB. It represents the boundary between what is considered to be an
ionic or a covalent bond.
C. It determines if the 2 atoms will react to form a molecule.
D. It identifies which metal atoms will join together to form metallic
bonds
Am
B. It represents the boundary between what is considered to be an ionic or a covalent bond.
Further explanationElectronegativity is the ability of atoms to attract electrons, especially in covalent bonds (sharing of electron pairs)
In a periodic system, electronegativity increases in a group, from bottom to top, and in a period from left to right.
From this difference in electronegativity, we can determine the ionic compound, polar or non-polar
Pauling determined the electronegativity scale (based on bond energies), between 0.7 - 4 (Fluorine has the highest number of electronegativities: 4)
Polar covalent compounds have a large electronegativity difference, while nonpolar compounds have a small electronegativity difference.
We can use the difference in electronegativity between the 2 bonded atoms to determine their polarity
<0.5: covalent non polar 0.5- 1.7: covalent polar > 1.7 : ionExample
H₂OH = 2.1
O = 3.5
H₂O = 3.5-2.1 = 1.4 >> polar
O₂= 3.5-3.5 = 0 >> non polar
Which of the following wave types must have a medium to travel?
A. Ultraviolet light
B. Microwaves
C. Seismic (earthquake) waves
D. Radio waves
E. X rays
Answer:
it is B
Explanation:
Answer: B microwaves
the ability for a substance to rust is
a. oxidation
b.rustability
c.magnetic attraction
d.reactivity
Answer:
i think it is letter b. rustability but not so sureeee
What’s this called please help
Answer:
the answer is a linear
Explanation:
heres a graph different ones at this link
Why is the nitrogen cycle considered a closed system?
Answer:
because nitrogen is fixed by bacteria and assimilated by plants
Explanation:
Answer:
It is a considered a closed system because nitrogen is fixed by bacteria and is taken in by plants.
Explanation:
True or false
Each family represents the number of energy levels present in an atom of the element.
Answer:
true because of the elements
HELP ASAPP JUST TELL ME WHAT TO PUT IN THE MISSING SPACES words(cell,microorganisms,micrometer,microscopic,molecule)
Answer:
microorganisms, molecule, microscopic, cell, micrometer
Explanation:
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i need help please!
asap
Answer:
Earth is pulling up on the book with a force of 4n i think
Explanation:
What are the reactants of photosynthesis?
Answer:
The photosynthesis chemical equation states that the reactants (carbon dioxide, water and sunlight), yield two products, glucose and oxygen gas. The single chemical equation represents the overall process of photosynthesis.
Explanation:
A car travels 45 miles per hour. What is this speed in feet per hour?
Answer:
64
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Please help ASAP 100 points points help I will mark you as brainlister
this is lithium ion with a +1 charge
Which is the IUPAC name for NO?
nitric oxide
binitrogen oxide
dinitrogen dioxide
nitrogen monoxide
The IUPAC name for NO is nitric oxide. The correct option is A.
What is IUPAC naming?The International Union of Pure and Applied Chemistry (IUPAC) is a global organization that represents chemistry as well as related sciences and technologies.
The chemical compound's identity is represented by its common and IUPAC names, which differ from one another. Every chemical compound has multiple names.
Complete the following step-by-step response: The IUPAC nomenclature is a standardized name given to organic compounds in accordance with official naming rules.
Nitric oxide, also known as NO, is a colorless gas. It is one of the most important nitrogen oxides.
Nitric oxide is a free radical, which means it has an unpaired electron, which is sometimes represented in its chemical formula by a dot.
Thus, the correct option is A.
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Answer:
D: Nitrogen Monoxide
Explanation:
There's one Nitrogen atom and one Oxygen atom
8. Describe how crystals of copper sulphate are prepared.
Answer:
Take a cupful of water in a beaker and add a few drops of dilute sulphuric acid. Heat the water. When it starts boiling, add copper sulphate powder slowly while stirring continuously. ... Crystals of copper sulphate will be seen at the bottom of the beaker.
Hope it helps
helppppppppppppp plzzzzzzzz Identify each structure based on its label.
Compound A is a
amine.
Compound B is a
amine.
Compound C is a
amine.
Compound D is
.
Answer:
kldja
Explanation:
A.) primary
B.) tertiary
C.) secondary
D.) ammonia
edge2020
Describe the specific steps a scientist would take to solve a particular problem
Answer:
scientific method
Explanation:
- make an observation
- ask a question
- form a hypothesis
- make a prediction based on the hypothesis
- test the prediction
- iterate: use the results to make new hypotheses or predictions
WILL MARK BRAINLIEST!!!! HELPPPP
what is the difference between simple distillation and fractional distillation
Answer:
A single distillation cycle is enough to separate the mixture. ... Simple distillation is the method used to separate substances in mixtures with significantly different boiling points, while fractional distillation is used for mixtures containing chemicals with boiling points close to each other.
Explanation: