rays with short wavelengths that are the least penetrating, produce chemical effects, and kill germs are
Answer:ultraviolet rays
Explanation:
An atom's Lewis dot structure has three dots. Which of the following elements could it be, and why? (4 points)
Group of answer choices
Aluminum, because it is in group 13 and has three valence electrons.
Lithium, because it is a group 1 element with three total electrons.
Magnesium, because it is in period 3 and has three valence electrons.
Potassium, because it is an alkali metal and has three inner shell electrons.
Answer : The correct option is, Magnesium because it is a group 2 element with two valence electrons.
Explanation :
Element = Calcium
Atomic number = 20
Electronic configuration of Ca =
Number of valence electrons in Ca = 2
The number of inner shell electrons in Ca = 18
This option is wrong because lewis-dot structure shows only valence electrons not inner shell electrons.
Element = Carbon
Atomic number = 6
Electronic configuration of C =
Number of valence electrons in C = 4
This option is wrong because only outermost p-sublevel electrons are not showing in lewis-dot structure.
Element = Lithium
Atomic number = 3
Electronic configuration of Li =
Number of valence electrons in Li = 1
This option is wrong because it has only 1 electron in outermost shell.
Element = Magnesium
Atomic number = 12
Electronic configuration of Ma =
Number of valence electrons in Ma = 3
This option is correct.
Lewis-dot structure : It is defined as the structure in which valence electrons of the atom is shown as dots.
ANOTHER EXPLANATION:
Answer: C. Magnesium, because it is a group 2 element with two valence electrons.
An atom's Lewis dot structure has two dots. Which of the following elements could it be, and why?
A. Calcium, because it is an alkaline earth metal with two inner shell electrons.
B. Carbon, because it has two electrons in its outermost p sublevel.
C. Lithium, because it is a group 1 element with two bonding electrons.
D. Magnesium, because it is a group 2 element with two valence electrons.
Explanation:
If you were to look at the periodic table magnesium would be in group 2. Since magnesium is in group 2 therefore it will have two valence electrons. Calcium is another possible answer because it is also in group two, but for this quiz it is incorrect. Lithium is incorrect because it is in group 1 and therefore it would only have 1 valence electron. Carbon is also incorrect because it is in group 14 so it would have 4 valence electrons. Hope this helps and makes sense.
Good Luck!!
Have a great day Studying!
The Lewis dot structure of an atom has three dots. With three valence electrons and belonging to group 13, which of the following elements may it be?
Are the elements of group 13 metals?The semi-metal boron (B) and the metals aluminum (Al), gallium (Ga), indium (In), and thallium (In) are all members of the boron family (Tl). The periodic table's fifth element, boron (Z=5), is found in Group 13. It is categorized as a metalloid because of its characteristics, which combine those of metals and nonmetals.
What traits does group 13 exhibit?The Periodic Table of Elements places these elements in Group 13 (XIII) of the p block. Metallic elements include thallium, gallium, indium, and aluminum. In their outermost shells, they each have three electrons shell with the valence electron configuration ns2np1 (one electron in the p orbital and a complete s orbital).
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what are the statement of ethanol
Answer:
Density 0.78945 g/cm3 (at 20 °C)
Melting point −114.14 ± 0.03 °C (−173.45 ± 0.05 °F; 159.01 ± 0.03 K)
Boiling point 78.23 ± 0.09 °C (172.81 ± 0.16 °F; 351.38 ± 0.09 K)
Solubility in water Miscible
Explanation:
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What makes inertia important in that activity?
plesse hurry aand help with QQQQQ
Answer: the answer should be A the first one
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the properties of a substance that can be observed without altering its identify physical property. true false ?
Answer:
True
Explanation:
A physical property is a characteristic of a substance that can be observed or measured without changing the identity of the substance. Physical properties include color, density, hardness, and melting and boiling points.
What’s solubility need it for science
Answer:
the ability of a compound to dissolve
Explanation:
salt dissolves in water so it would be soluble.
oil does not dissolve in water so it is not soluble
mmmmmmmmmmmmmtyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy
Answer:
Yes.
Explanation:
Answer:
=0=0==00=0=0=
Explanation:
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What is considered a pure substance?
Answer:
A substance that has a fixed chemical composition throughout is called a pure substance such as water, air, and nitrogen. A pure substance does not have to be of a single element or compound.
Explanation:
Compound: A substance that contains more than one element
pure substance: is made up of one substance made up of only one type of molecule
I need help with this
Answer:
129 units cubed
Explanation:
There are ten spaces between 120 and 130, so we can infer that each line represents a change in volume of 1 unit. The volume of the substance in the graduated cylinder looks like it's 1 under 130, so its volume is 129 units.
Hopefully this was helpful! :)
A chemist measured the temperature of a liquid to be 26 ∘C, then she heated the liquid to 83 ∘C. By how many Kelvins did the temperature change.
Answer: 57.C
Explanation: simple subtraction
The temperature of a gas is increased. Which statement best explains the effect that this has on the motion of gas
particles?
Answer:
The average kinetic energy increases, and the particles collide more frequently.
Explanation:
A GIRL WAIKS 10M NORTH,15M EAST AND THEN FINALLY 20MSOUTH FIND HER DISPLACEMENT
Answer:
see this
Explanation:
What is an activation energy
Answer:
Defination of Activation energy :- In chemistry and physics, activation energy is the minimum amount of energy that must be provided for compounds to result in a chemical reaction. The activation energy of a reaction is measured in joules per mole, kilojoules per mole or kilocalories per mole. Meaning of Activation energy :- The minimum quantity of energy which the reacting species must possess in order to undergo a specified reaction.Explanation:
Hope this helps you dear ✌️Carry on learning !!could you help answer these two question
Answer:
number 29 is D
Explanation: When the moon orbits the earth some of the light reflects off the moon, making it visible on the Earth.
I dont know how to answer 28 fully, is there a picture?
whats valency of nitrogen in N2O3, N2O5 and NO
Answer:
Valency of nitrogen in the given compounds:
N₂O₃ = +3
N₂O₅ = +5
NO = +2
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a student is given a mixture of sand and salt. describe a method the student could use to separate the mixture.
There is a golden role of solubility, polar solute dissolve in polar solvent and non polar solute dissolve in non polar solvent. Therefore, Salt and sand can be separated by dissolving the salt in water, filtering the mixture, and then evaporating the water to recover the salt.
What is solution?Solutions are a homogeneous mixture of two or more substances. A solution is a homogeneous mixture of solvent and solute molecules. Solvent is a substance that is in large amount in solution.
Solute is the substance which is in small amount in a solution. Salt and sand can be separated by dissolving the salt in water, filtering the mixture, and then evaporating the water to recover the salt.
Therefore, Salt and sand can be separated by dissolving the salt in water, filtering the mixture, and then evaporating the water to recover the salt.
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need help w this question
Answer:
ok you got it you just need to add.
Explanation:
add 5 times and she what you get.
What is the most common injury caused by working with machines unsafely?
Answer:
The most common injury caused by working with machinery are cuts and burns.
Explanation:
Cuts and burns are the most common injury caused by working with machines unsafely.
What is injury?Any physiological harm to living tissue brought on by acute physical stress is referred to as an injury. An injury can be brought on by a blunt trauma, a piercing trauma, burning, exposure to chemicals, asphyxiation, or overexertion, and it can also happen accidentally. Any area of the body can become injured, and each injury has a unique set of symptoms.
Major injuries are normally treated by a medical practitioner, and the type of treatment depends considerably on the injury. The most frequent reason for accidental human injury or injury-related death is traffic crashes. Chronic conditions are different from injuries. Cuts and burns are the most common injury caused by working with machines unsafely.
Therefore, Cuts and burns are the most common injury caused by working with machines unsafely.
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PLEASEEE ANSWER PLEASEEE PLEASE I’ll mark brainliest
Answer:
Lithium has 1 valence electron, Sulfur has 6
A is oxidized, B is reduced
A is reducing agent, B is oxidizing agent
Explanation:
when an atom loses electrons, it is oxidized
when an atom gains electrons, it is reduced (almost think of when you add a negative number to a positive number, the positive number gets smaller or is reduced)
Why is knowledge of the activity series crucial in choosing which metal to build things with?
Answer:
activity series is a list of substances ranked in order of relative reactivity.
For example, magnesium metal can displace hydrogen ions from solution. So magnesium is more reactive than hydrogen:
Mg(s) + 2H⁺(aq) → H₂(g) + Mg²⁺(aq)
Zinc metal can also displace hydrogen ions from solution:
Zn(s) + 2H⁺(aq) → H₂(g) + Zn²⁺(aq)
so zinc is also more active than hydrogen.
But magnesium metal can displace zinc ions from solution:
Mg(s) + Zn²⁺(aq) → Zn(s) + Mg²⁺(aq)
so magnesium is more active than zinc.
The activity series including these elements would be Mg > Zn > H.
Chemists have built up a complete activity series in a similar way.
The most active metals are at the top of the table; the least active are at the bottom.
Any metal that is higher in the series will displace a metal that is below it in a
The knowledge of the activity series in choosing which metal to build things with because; it provides a basis for determining which metal ion is able to displace the other upon chemical interaction.
The choice of building material is a very important design consideration.
This is so because careful consideration must be taken while deciding which metal to build things with as the reactivity of metals vary.This variation is carefully quantified by the position of metals on the activity series.
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assuming that no heat is lost to the surroundings, what is the final temperature of the mixture?
how is a standard hydrogen atom different from a hydrogen ion?
Answer:
a hydrogen ion will have more or fewer electrons than a standard hydrogen atom.
Explanation:
ions are atoms that have lost or gained elections. this applies to ions in general.
covalent bond of N and S
Answer:
Covalent bond between identical atoms
Covalent bonds occur between identical atoms or between different atoms whose difference in electronegativity is insufficient to allow transfer of electrons to form ions. ... The two hydrogen atoms are attracted to the same pair of electrons in the covalent bond.
What is the total number of neutrons in an atom of O-18? a) 18 b) 16 c) 10 d) 8
Answer:
There are 10 neutrons
Explanation:
Because the atomic number is 8 and the isotope number is 18 (which is the collective protons and neutrons), we can do
18-8=10
Answer:
10
Explanation:
8 proton because it is oxygen
10 neutron because 18-8
Where does the energy of a hurricane come from? (1 point)
O the Sun
O strong winds
O Earth's spin
O Earth's moon
Answer:
strong winds come from the energy of a hurricane
The energy of a hurricane come from strong wind. The Taino Native American term hurricane, which translates to "bad spirit of the wind," is where the word hurricane originates.
What is hurricane ?A tropical storm that has sustained winds of 74 mph or greater is referred regarded as a hurricane. A storm's eye typically measures 20 to 30 miles in width and can reach distances of 400 miles. Storms can be dangerous because of their torrential downpours, strong gusts, and storm surges.
When warm, humid air begins to rise over water, hurricanes emerge. Cooler air replaces the rising air. Large clouds and thunderstorms continue to grow as a result of this process. Thanks to the earth's Coriolis Effect, these thunderstorms are still expanding and starting to rotate.
Thus, option B is correct.
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A student draws a model of one of the sun's layers. The student draws arrows to represent hot gas moving away from the center of the sun and other arrows to represent cool gas moving toward the center of the sun. Which layer does the model show?
Radiation Zone
Convection Zone
Chromosphere
Inner Core
Answer:
The convection zone :)
What is acid rainnnnnn
Answer:
ACID RAIN
Explanation:
duh
Ethanoic acid is a weak acid because
Is a carboxylic acid
Does not irritate the skin
Is not completely ionized in water
Produces one hydrogen ion per molecule
Answer:
is not completely ionized in water
The ethanoic acid (acetic acid) is considered as a weak acid because it does not releases all of its hydrogen in water, rather it dissociates partially and establishes an equilibrium with its conjugate base.
What fraction of the original atoms of the radioactive sample will remain after the given number of half-lives has passed?
Answer:
1/8
Explanation:
[tex] \frac{1}{ {2}^{3} } = \frac{1}{8} [/tex]
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