write a short note on importance of air
PLEASE ANSWER ASAP NEED ANSWER!!!!!!!!!!!!!! 75 POINTS
Which statement about pure substances and molecules is correct?
A. Pure substances cannot be molecules.
B. All molecules are pure substances.
C. Molecules cannot be pure substances.
D. All pure substances are molecules.
Answer:
D. All pure substances are molecules.
The correct statement about pure substances is; "All molecules are pure substances."
A pure substance contains exactly the same type of atoms. In a molecule, there can only be a particular combination of atoms.
For instance, a molecule of HCl can only contain chlorine and hydrogen atoms.
This means that every molecules are also pure substances.
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write any two effect of gravity
Which statement about an atom is correct? (1 point)
O The proton has no charge and is found in the nucleus.
O The neutron has no charge and is found outside of the nucleus.
O The neutron has a negative charge and is found in the nucleus.
o The electron has a negative charge and iş found outside of the nucleus.
Answer:
D. the electron has a neg. charge and is found outside of the nucleus.
Explanation:
the proton has a positive charge, while the neutron has no charge at all. both are found in the nucleus.
the electron has a negative charge, but stays outside of the nucleus in the electron cloud, constantly moving around.
Taking into account the constitution of an atom, the correct statement is "The electron has a negative charge and iş found outside of the nucleus."
An atom is the smallest constituent unit of ordinary matter that has the properties of a chemical element.
Every atom consists of:
A nucleus in which neutrons and protons meet. Energy levels where electrons are located.In other words, the atomic nucleus is the central part of the atom that is made up of protons and neutrons, while the orbitals or peripheral region is an area where electrons are found.
The neutron is an electrically neutral subatomic particle, while the proton has a positive electrical charge. Electrons have a negative charge, move around the nucleus at different energy levels and are attracted to protons, positive in the atom through electromagnetic force.
In summary, the correct statement is "The electron has a negative charge and iş found outside of the nucleus."
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https://brainly.com/question/1814899?referrer=searchResultshttps://brainly.com/question/2449569?referrer=searchResultsThe lines of latitude are measured
from a line at the center of the Earth
called the
Answer:
parallels
Explanation:
hope it may help you
Write the chemical symbols for three different atoms or atomic cations with 11 electrons.
Three ways to represent atoms or atomic cations with 11 electrons include :
[tex] {Mg}^{ + } \: {Al}^{2 + } \: {Si}^{3 + } [/tex]
Mg = magnesium has 12 electrons in its neutral state, when it loses one electron to attain stability, it's election becomes 11.
Al = Aluminum has 13 electrons in its neutral state, when it donates 2 electron to attain stability, it becomes (13 - 2). = 11
Si = Silicon has 14 electrons on it's neutral state, when it loses 3 electrons to attain stability, we have (14 - 3) = 11
Hence,
[tex]{Mg}^{ + } \: {Al}^{2 + } \: {Si}^{3 + } [/tex]
are atomic cations with 11 electrons.
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What types of atoms typically form covalent bonds?
Answer: In a covalent bond, the atoms bond by sharing electrons. Covalent bonds usually occur between nonmetals. For example, in water (H2O) each hydrogen (H) and oxygen (O) share a pair of electrons to make a molecule of two hydrogen atoms single bonded to a single oxygen atom.
Explanation:
A variable parameter
a. does not affect the result.
b. is the factor that changes in an experiment.
C. cannot change.
d. is rarely included in experiments.
Answer
b.
Explanation:
variable means change bro
The ideal gas constant R can be denoted as _______.
A. R = 9.315 (Pa × m3) / (mole × K)
B. R = 9.315 J / (mole × K)
C. R = 0.0821 (L × atm) / (mole × K)
D. All of the Above E. None of the Above
is time a fundamental quantities or units?
Answer: Its fundamental quantities
The SI is on the seven SI base units for seven base quantities.
pls mark brainliest
a transistor has beta=180 calculate the approximate collector and base currents if the emitter current is 10ma
Answer:
kausvsnks
Explanation:
bdjwkagsjwlak
How many elements
make up hydrogen
Answer:
hydrogen is 1 element but has 2 atoms
The mass of all the water on earth is 1.4 x 1024 grams. How do you think
someone was able to measure that number?
Evolution means..... exchanges gradual development transcription differentiation
Explanation:
Evolution means Gradual Development. It is a procedure in the gradual development in which species of different animal's, plants etc... leisurely started to change some of their activities or elements and it changes only due to some situations it changes over many generations also.
Answer:
mark me as a brainlist answer i hope it will help you
Explanation:
Evolution means Gradual Development. It is a procedure in the gradual development in which species of different animal's, plants etc... leisurely started to change some of their activities or elements and it changes only due to some situations it changes over many generations also.
the internacional system of units is based on ?
Answer:
The international system of units is basic on 7 units.
Hope it helps you.how many hours are in 25 years?
According to the molecular orbital theory how many molecular orbitals are formed when six p-orbitals of benzene combine?A) 6B) 5C) 4D) 3E) 2
there are 6 orbitals are formed when six p- orbitals of benzene combine.
30 POINTS!
Which parts are only found in plant cells?
Answer:
A B and F
Explanation:
.................
Please help!!! Question 1 to 8
Answer:
1) C - 30
2) A - MgO
3) C - 3Cu + N2 + 3H2O
4) C - 100
Explanation:
0.5 mole of Na2SO4 x 10 H2O consists of what
Answer:
» It contains two atoms of sodium sulphate
» It contains 10 molecules of water.
Consider the addition of NaCl to the ice-water mix in Part II. Which of the following statements is TRUE?
a. Salt lowers the freezing point of water by interfering with the intermolecular forces of the water molecules, allowing for more interactions between water molecules.
b. Salt lowers the freezing point of water by interfering with the intermolecular forces of the water molecules, allowing for less interactions between water molecules.
c. Salt raises the freezing point of water by interfering with the intermolecular forces of the water molecules, allowing for less interactions between water molecules
d. None of the above are correct.
Salt lowers the freezing point of water by interfering with the intermolecular forces of the water molecules, allowing for less interactions between water molecules.
What is freezing point?The Freezing point is the temperature of a liquid at which it changes its state from liquid to solid at atmospheric pressure.
Salt molecules block water molecules from packing together when temperature is lowered. It then prevents them from becoming ice. More water molecules leave the solid phase than the ones entering the solid phase. Freezing point depression occurs when the freezing point of the liquid is lowered by addition of solute.
Hence, option B is correct.
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examps of sources of primary pollutants
Answer:
Primary pollutants can be emitted from many sources including cars, coal-fired power plants, natural gas power plants, biomass burning, natural forest fires, volcanoes, and many more. The effects of primary pollutants are of concern as they can be harmful to humans, animals and plants.Sep 3, 2018
Explanation:
A primary source results from the direct emissions from an air pollution source. In contrast, a secondary source results from the formation of a pollutant in the atmosphere from the chemical reaction of precursors emitted from air pollution sources.
PLEASE SOLVE THIS QUESTION.
VERY MUCH IMPORTANT
Answer:
[tex]thank \: you[/tex]
3(b) The balloon did not burst when it is pressed onto 100 nails because
1. the nails are not sharp
2.the surface area of 100 nails produce high pressure on the balloon
3. the larger surface area of 100 nails produce low pressure on the balloon
3(c) To reduce pressure on the contact surface, we must apply force onto the .................... surface area.
1.largest
2.smallest
3. Any size of
The atomic size of atoms ________. A) increases going across a period B) decreases going down within a group C) increases going down within a group D) does not change going down within a group
Answer: my answer is A) increases going across a period
Explanation: because of it nuclear charge as it increases going across a period
HOPE THIS HELPSSSSS!!
AM AWARDING BRAINLIEST :))
Re-order each list of elements in the table below so that the elements are listed in order of decreasing electronegativity
1) Cl, Br, F
2) B, 0, C
what is the source of energy that is absorbed by the electrons to move from the ground state to excited state?
Answer:
I think an atom changes from a ground state to an excited state by taking on energy from its surroundings in a process called absorption. The electron absorbs the energy and jumps to a higher energy level. In the reverse process, emission, the electron returns to the ground state by releasing the extra energy it absorbed.
I hope this help you!:)
If a stronger solution of sodium bicarbonate was used in beaker C, would it require more or less hydrochloric acid to neutralize and why?
Part A; A stronger solution of sodium bicarbonate require more hydrochloric acid will be required
Part A; The reason why more HCl is required is due to the presence of more hydroxyl ions in the solution
The reason arriving at the above responses are as follows;
Part A
Sodium bicarbonate, NaHCO₃, is baking soda = A basic salt; has the capacity to deprotonate water
Hydrochloric acid, HCl = An acid
The reaction between sodium bicarbonate and hydrochloric acid is presented as follows;
NaHCO₃ + HCl → CO₂ + H₂O + NaCl
The equation for the ionic reaction is as follows;
Na⁺(aq) + HCO₃⁻(aq) + H⁺(aq) + Cl⁻(aq) → Na⁺(aq) + Cl⁻(aq) + H₂O(l) + CO₂(g)
In water, we have;
HCO₃⁻(aq) + H₂O(l) ⇄ H₂CO₃(aq) + OH⁻(aq)
The presence of a stronger solution of sodium bicarbonate, will produce more hydroxyl ions, OH⁻(aq), which will require, more HCl to neutralize
Therefore, if a stronger solution of sodium bicarbonate was used, more hydrochloric acid will be required
Part B
The solution of stronger sodium bicarbonate will contain a higher concentration of hydroxyl ions and therefore, require more HCl, to neutralize
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The Coca- cola is diluted and reacted with molybdate/metavanadate reagent before the %T is measured.
a. True
b. False
Answer:
true
Explanation:
I believe that is the correct answer (if right brainiest plz)
How many significant figures are in 4500000. mL?
Explanation:
1 significant figure and 0 decimal