When do you identify your variables?
After the results
After the conclusion
Before the hypothesis
Before the question
Answer:
Before the hypothesis
Explanation:
The picture provided shows the arrangement of electrons in atomic shells around the nucleus of four different elements.
Which statement is true about these elements?
A) All elements belong to the same period.
B) All elements belong to the same group.
C) Elements 1 and 4 belong to the same group.
D) Elements 2 and 3 belong to the same period.
Both element 1 and element 4 have one electron in their valence shell Therefore, they belong to the same group. Therefore, option (C) is correct.
Why do elements of the same group have similar chemical behavior?The chemical behavior of elements will depend on the number of electrons in their outermost shell. Elements that are placed in the same group have the same number of valence electrons. Therefore, elements present in the same group of the modern periodic table have similar chemical properties.
The elements with a similar outer shell electronic configuration in their atoms are organized in the same group of the modern periodic table. These valence electrons of an element are responsible their chemical properties and reactivities of the elements.
Elements 1 and 4 have one electron in their valence shell so they belong to the same group while elements 2 and 4 have two electrons in their valence shell that also belong to the same group.
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Why did workers form labor unions?
Answer:
Labor unions were created in order to help the workers with work-related difficulties such as low pay, unsafe or unsanitary working conditions, long hours, and other situations. ... Sometimes the unions organized strikes in order to try to change the conditions of the workers.
Explanation:
Answer:
to speak with one voice
Explanation:
a p e x
which one of the following groups are decomposers a. algae b. protist c. fungi d. green plants e. photosynthetic bacteria?
Answer:
c. fungi
Explanation:
Decomposers are organisms that breaks down dead and decaying matter in nature. They derived their nourishment by breaking down other complex organic matter.
Fungi are a group of organisms that are mainly decomposers.
They recyclers in nature.
Green plants and photosynthetic bacteria are similar in that they obtain nourishment by the use of light to initiate the reaction between carbon dioxide and water.
Many protists are decomposers but not all.
What is the definition of hydro energy
Answer:
a form of energy that harnesses the power of water in motion—such as water flowing over a waterfall—to generate electricity.
Explanation
In Step 5, you will calculate H+/OH– ratios for more extreme pH solutions. Find the concentration of H+ ions to OH– ions listed in Table B of your Student Guide for a solution at a pH = 2. Then divide the H+ concentration by the OH– concentration. Record these concentrations and ratio in Table C. What is the concentration of H+ ions at a pH = 2? mol/L What is the concentration of OH– ions at a pH = 2? mol/L What is the ratio of H+ ions to OH– ions at a pH = 2? : 1
The ratio of H⁺ ions to OH⁻ ions at a pH = 2 is 10¹⁰
Further explanationGiven
ph = 2
Required
The concentration of H⁺ and OH⁻ ions
Solution
The concentration of H⁺ ionspH=-log[H⁺]
2=-log[H⁺]
[H⁺]=10⁻²
The concentration of OH⁻ ionspH+pOH=14
pOH=14-2
pOH=12
pOH=-log[OH⁻]
12=-log[OH⁻]
[OH⁻]=10⁻¹²
The ratio of H⁺ ions to OH⁻ ions at a pH = 2[tex]\tt \dfrac{10^{-2}}{10^{-12}}=10^{10}[/tex]
Answer:
First one: 0.01
second one: 0.000000000001
third one: 10000000000
PWEaseee help mweee ill mark brainliest I just need the answer pls and thank you amazing people
1 Aluminum reacts with oxygen to produce aluminum oxide, what is the chemical equation?
Answer: Aluminum reacts with oxygen to produce aluminum oxide as follows: 4Al + 3O2 → 2Al2O3 a.
Explanation: I really really hope that was helpful.
What is a photon???????????
A photon is a fundamental particle of light that carries energy and behaves both as a particle and a wave.
It carries electromagnetic waves like visible light, radio waves, X-rays, and gamma rays. Photons have energy, momentum, and angular momentum but no mass.
Photons are particles and waves in quantum physics. They absorb, emit, and scatter stuff at the speed of light in a vacuum. Photons excite electrons in atoms and molecules, starting physical and chemical reactions.
E = hf, where E is the photon's energy, h is Planck's constant, and f is its frequency. Quantum physics relies on photons to comprehend light and matter interactions.
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Which of these metals is the least reactive?
in
caldum
sodium
potassium
Answer:
Calcium
Explanation:
It is because sodium and potassium are highly reactive metal i.e. Group 1 but calcium is Group 2 element. So, calcium is least reactive.
pls asap figure it out pls I will mark brainliest
Answer:
NaCl (Na is a metal and Cl is a nonmetal) MgO (Mg is a metal and O is a nonmetal) Al2O3, NaF, Na2O
Explanation:
You have to have a metal and a non metal together for it to be ionic
Synthesis
Decompisition
O Combustion
O Single Displacement
O Double Displacement
Answer:
Synthesis
Explanation:
Nothing else works
5. What charge does iron have in iron (111) oxide?
Answer:
0
Explanation:
Explain how the need for energy is the driving force of the oxygen cycle.
Yet again earth science
Answer:
Engery is the driving force of the oxygen cycle is photosynthesis itself, which is responsible for the creation and maintenance of earth's atmosphere.Plants are able to use the energy of sunlight to convert carbon dioxide and water into carbohydrates and oxygen.
Answer:
Energy is the main force of the oxygen cycle and not to mention also photosynthesis, which is responsible for the creation of the earth's atmosphere. This would also mean that plants are the main focus of the Oxygen cycle and energy is needed to make plants. So without energy, no plants would exist! Not to mention the oxygen cycle wouldn't work without energy. Plants are also able to use the energy of sunlight to convert carbon dioxide and water into carbohydrates and oxygen.
Hope this helps! :)
Explanation:
3. Which of the following claims do NOT a limitation of Bohr's model? *
Electrons in an orbital have constant energy
Electrons can exist in between energy levels
Electrons must absorb a quantum to move up an energy level
Electrons behave like particles
Answer:
B. Electrons can exist in between energy levels .
Explanation:
The value of energy for each energy level in an atom is quantized. Thus, electrons are not allowed to be found in between the energy levels.
When an electron absorbs energy, it becomes excited. And it would jump to a higher energy level whose energy is equal to the new energy of the electron. If the value of its new energy is less than the energy of higher levels but greater than the energy of it current energy level, the electron remains in its initial level. This is because, electrons do not exist in between energy levels .
How is gamma radiation produced?
Answer:
They are produced by the hottest and most energetic objects in the universe, such as neutron stars and pulsars, supernova explosions, and regions around black holes. On Earth, gamma waves are generated by nuclear explosions, lightning, and the less dramatic activity of radioactive decay.
Describe the subatomic particles found in an atom, and
describe each one. Also, describe how they relate to each
other.
pls helpp <3
Horsetails are helpful for treating
bee stings.
fevers.
urinary tract infections.
bleeding injuries.
Answer:
urinary tract infections. B
Explanation:
What is an example of an initiation phase for an addition
polymerization reaction?
SELECT AN ANSWER
H-O* + CH3-CH3 ----> H-O-CH2-CH2*
H-O* + CH3-CH3 ----> H-O-CH2-CH2-O-H
H-O* + CH2=CH * ----> CH3CH2*
H-O* + CH2=CH2 ----> H-O-CH2-CH2*
Answer:
H-O* + CH3-CH3 ----> H-O-CH2-CH2*
H-O* + CH[tex]_3[/tex]-CH[tex]_3[/tex] → H-O-CH[tex]_2[/tex]-CH[tex]_2[/tex]* is an example of an initiation phase for an addition polymerization reaction. Therefore, the correct option is option A.
What is polymerization reaction?High-molecular-weight compounds known as polymers are created by the aggregation of several smaller molecules known as monomers. Polymers make up the natural and manmade fibres used in clothes as well as the polymers that have revolutionised society.
Two fundamental methods for creating polymers exist: (a) joining small molecules together by an addition reaction, and (b) joining molecules while getting rid of a stable small molecule like water. Condensation processes, which combine addition and elimination reactions, are what this later type of polymerization is known as. H-O* + CH[tex]_3[/tex]-CH[tex]_3[/tex] → H-O-CH[tex]_2[/tex]-CH[tex]_2[/tex]* is an example of an initiation phase for an addition polymerization reaction.
Therefore, the correct option is option A.
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I've decided that i still want to have some orange juice
Answer:
Oh thats great..
But I hate juice :(
If a concentrated solution of acetic acid is 99.5 % HC2 H3 O2 and has a density of 1.05 g/mL, what is the concentration of this acid in moles per litre?
Answer:
[CH₃COOH] = 17.4 M
Explanation:
Acetic acid → CH₃COOH
Molar mass → 60 g/mol
99.5% is percent by mass concentration. It means that 99.5 grams of solute are contained in 100g of solution.
Density → 1.05 g/mL. This data is always referred to solution, not solute!.
We determine solution's volume:
1.05 g/mL = 100 g / V → V = 100 g /1.05 g/mL → 95.2 mL
Now we know, that 99.5 g of acetic acid are contained in 95.2 mL
Let's convert to mmoles → 99.5 g / 60 g/mol = 1.66 moles
We convert solution's volume to L → 95.2 mL . 1L / 1000 mL = 0.0952 L
M (mol/L) = 1.66 mol / 0.0952 L = 17.4 M
Which safety procedure could prevent an accident?
using a fire extinguisher
using glass without chips or cracks
smelling a mixture of chemicals
getting a bandage out of the first aid kit when bleeding
Answer:
B
Explanation:
What is the percent composition of Phosphorus in Li3PO3
Answer:
you will get 17.983 g of lithium for every 100 g of lithium phosphate.
Explanation:
69.7% is the percent by mass of Lithium in Li[tex]_3[/tex]PO[tex]_3[/tex]. A percent is obtained by multiplying the result by 100.
One approach to show the concentration for an element within a compound or component in a combination is as a mass percentage. The mass percentage is computed by dividing the total weight of the combination by the mass of each component and multiplying the result by 100%. The mass percent is calculated by dividing the mass that contains the compound and solute by the mass for the element or solute.
99.795g/mol = molar mass of Li[tex]_3[/tex]PO[tex]_3[/tex]
6.94g/mol = molar mass of Li
mass percentage of Li=(molar mass of Li/molar mass of Li[tex]_3[/tex]PO[tex]_3[/tex])× 100
=(6.94/99.7)× 100
=69.7%
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An electrically neutral atom consists of 15 neutrons,13 electrons, and a number of protons.what is its mass number
Answer:
28
Explanation:
The atom is neutral, which means the quantity of electrons and protons square measure an equivalent. thus if there square measure 13 electrons, there square measure 13 protons. and therefore the nucleon number is neutrons and protons. thus 13+15 is 28
The prefix "semi-" means "partly". Based on your knowledge of the properties of elements, which kind of element is most likely used to make semiconductors?
liquids
metalloids
metals
nonmetals
Answer:
metalloids
Explanation:
The kind of element most likely used to make semiconductors are the metalloids.
These elements have properties between those of metals and non-metals in that they are not truly metals and are partly non-metals.
Under certain conditions they show features of metals or non - metals. The class of these elements are the metalloids. They are used to make semiconductors which are major components of electronics.Question
Your boss is required to provide job safety training:
A) only if you request the training
B) as soon as there are a sufficient number of new employees
C) before you start your job
D) within the first year of your new job
Answer:
C) before you start your job
Explanation:
its the 1st thing to do when ur on a job...i guess not sure but try it anyway....but if im wrong blame
Answer:
I think it's c (before you start your job)
Explanation:
cuz we can get experienced after we are provided job safety training and it is also the first thing we will be given.
sorry if I'm wrong
which rock is the result of changes on the Earth's surface?
igneous rock
sedimentary rock
metamorphic rock
Answer:
metamorphic
Explanation:
when one rock changes another rock the rock that got changed is now metamorphic
Why do rappers need umbrellas?
Maybe to not get rained on.
Hahhahahaha I ain't sure tho
Answer:
Fo' drizzle.
Explanation:
name a lustrous non- metal ?
Answer:
it is iodine it seems very right
Someone solve b QUICK i’ll mark branliest
Answer :
(a) Reactant Mg is oxidized and reactant Fe is reduced.
(b) Reactant C is oxidized and reactant Cu is reduced.
Explanation :
As we know that a reactant is either reduced or oxidized in a chemical reaction.
If the oxidation state of an atom is decreases or gains electrons from reactant to product side then we can say that the reactant is reduced that means reduction.If the oxidation state of an atom is increases or loses electrons from reactant to product side then we can say that the reactant is oxidized that means oxidation.Part (a):
The given word equation of chemical reaction is:
Magnesium metal + Aqueous iron (III) sulphate → Iron metal + Aqueous magnesium sulphate
The balanced chemical equation of this word equation will be:
[tex]3Mg(s)+Fe_2(SO_4)_3(aq)\rightarrow 2Fe(s)+3MgSO_4(aq)[/tex]
In this reaction, the oxidation state of reactant Mg changes from (0) to (+2) that shows oxidation due to increase in oxidation state. So, we can say that Mg is oxidized.
And, the oxidation state of reactant Fe changes from (+3) to (0) that shows reduction due to decrease in oxidation state. So, we can say that Fe is reduced.
Part (b):
The given word equation of chemical reaction is:
Solid carbon + Solid copper oxide → Carbon dioxide gas + Copper metal
The balanced chemical equation of this word equation will be:
[tex]C(s)+2CuO(s)\rightarrow CO_2(g)+2Cu(s)[/tex]
In this reaction, the oxidation state of reactant C (carbon) changes from (0) to (+4) that shows oxidation due to increase in oxidation state. So, we can say that C is oxidized.
And, the oxidation state of reactant Cu changes from (+2) to (0) that shows reduction due to decrease in oxidation state. So, we can say that Cu is reduced.