Answer:
B. 20, 22, 20
Explanation:
The atomic number (Z) of calcium is 20, that is, it has 20 protons.
The mass number (A) of calcium-42 is 42. The mass number is equal to the sum of protons and neutrons. Then,
p⁺ + n⁰ = 42
n⁰ = 42 - p⁺
n⁰ = 42 - 20
n⁰ = 22
Since calcium is electrically neutral, it has the same number of protons (+) and electrons (-). Then, calcium has 20 electrons.
What is a "mole" in chemistry?
Answer:
Mole, also spelled mol, in chemistry, a standard scientific unit for measuring large quantities of very small entities such as atoms, molecules, or other
Answer:
Mole, also spelled mol, in chemistry, a standard scientific unit for measuring large quantities of very small entities such as atoms, molecules, or other specified particles.
Explanation:
A different brand of iron tablet was analysed by Hitration with 0.0093 mol.L" potassium
dichromate via the reaction listed below;
Cr2O72- + 6Fe2+ + 14H+ + 2Cr3+ + 6Fe3+ + 7H20
In this experiment 4 tablets were crushed and dissolved in 200 cm3 of dilute acid. 25cm3
of this solution was used in the titration. The results of the titrations were as follows;
Titration Volume dichromate (cm)
1
33.0
2
32.05
3
32.15
4
32.10
Calculate the concentration of iron used in the titration (4 dp).
C1V1/C2V2 = n/n2
The concentration of iron used in the titration : 0.009 M
Further explanationGiven
Reaction
Cr₂O₇²⁻ + 6Fe²⁺ + 14H⁺ ⇒ 2Cr³⁺ + 6Fe³⁺ + 7H₂O
0.0093 mol/L potassium dichromate
200 cm³ of dilute acid, 25cm³ was used in the titration.
Required
the concentration of iron
Solution
Titration formula
C₁V₁n₁=C₂V₂n₂⇒ From equation : n₁=6n₂(1=Cr₂O₇, 2=Fe)
titration average : 33+32.05+32.15+32.1 / 4 = 32.325 cm³(ml)
25 cm³ of iron solution used in titration :
[tex]\tt V_1=32.325~ml\\\\V_2=25~ml\\\\C_1=0.0093~M\\\\\\\\C_1.V_1.n_2=C_2.V_2.n_1\\\\0.0093\times 32.325\times 6=C_2\times 25\times 1\\\\C_2=0.07215~M[/tex]
Dilution(25 ml from 200 ml iron solution)
[tex]\tt C_2.V_2=C_1.V_1\\\\0.007215\times 25=C_1\times 200\\\\C_1=0.009~M[/tex]
What is the name of the compound with the formula LiNO3?
Answer:
Lithium nitrate
Explanation:
Lithium nitrate is an inorganic compound with the formula LiNO3. It is the lithium salt of nitric acid (an alkali metal nitrate).
Choose all the right answers.
Why do all machines lose some energy while they operate?
They run out of fuel.
Some heat radiates out.
Moving parts cause friction.
High pressure gases move the piston.
Answer:
They run out of fuel
Some heat radiates out
High pressure gases move the piston
Pieces of DNA that pass genetic traits from parent to offspring are what?
A. Heredity
B. Phenotype
C. Gene
D. Allele
Pieces of DNA that pass genetic traits from parent to offspring are called as gene.
What is DNA?DNA is a hereditary material which is present in human beings as well as all other living organisms. Every cell which is present in an organism's body has DNA which is the same. Most of the DNA is situated in the cell's nucleus and small amount of it can be found in the cell's mitochondria as well.
Information which is stored in DNA is stored as codes made up of four chemical bases namely, adenine, thymine , cytosine and guanine.Human DNA consists of 3 billion bases .The order of the bases determines information which is required for building and maintaining an organism.
DNA bases are capable of pairing up with each other. Adenine pairs with thymine and guanine pairs up with cytosine .Each base is also attached to a sugar molecule and a phosphate group. A base, phosphate sugar are together called as nucleotides.
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Are these synthesis decomposition single replacement or double replacement?
Answer:
1. Synthesis
2. Decomposition
3. Single replacement
4. Synthesis
5. Decomposition
6. Synthesis
Explanation:
Kind of a hard picture to look at but let me define each chemical reaction:
Synthesis:
a + b ---> ab In synthesis elements/compounds come together to form new compounds
Decomposition:
ab ---> a + b In decomposition a compound breaks down to form 2 elements/compounds
Single replacement:
a + bc ---> b + ac In a single replacement one element/compound takes the place of another element/compound.
Double replacement
ab + cd ---> ad + bc In a double replacement 2 compounds exchange different elements/compounds.
Now, let's go through the assignment
1. P + O2 --> P4O10 This is a synthesis reaction because the two elements (P and O) came together to form one compound.
2. HgO ---> Hg + O2 This is a decomposition reaction because HgO broke into separate elements Hg and O.
3. Cl2 + NaBr ---> NaCl + Br2 This is a single replacement reaction because chlorine (Cl) replaced the spot of bromine (Br) to bond with sodium (Na).
4. Mg + O2 ---> MgO This is a synthesis reaction because two elements (Mg and O) came together to form one compound.
5. Al2O3 ---> Al + O2 This is a decomposition reactions because Al2O3 broke into separate elements Al and O.
6. H2 + N2 ---> NH3 This is a synthesis reaction because two elements (H and N) came together to form one compound.
I hope this helps!!
- Kay :)
Given chemical equations are of following types which are given in serial order as synthesis,decomposition,replacement,synthesis,decomposition and synthesis reactions respectively.
1. It is a synthesis reaction because the two elements (P and O) came together to form one compound.
2. It is a decomposition reaction because HgO broke into separate elements Hg and O.
3. It is a single replacement reaction because chlorine (Cl) replaced the spot of bromine (Br) to bond with sodium (Na).
4. It is a synthesis reaction because two elements (Mg and O) came together to form one compound.
5. It is a decomposition reactions because aluminium oxide broke into separate elements Al and O.
6. It is a synthesis reaction because two elements (H and N) came together to form one compound.
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Heelllpp ASAP .............
Answer is
Chloromethane
Explanation: because c stand for carbon an the h stands for hydrogen and ci stands for
Chemical ionization
Anything that has mass and takes up space is what
0)
A
tass
B)
volume
)
density
D)
matter
Answer:
D - Matter
Explanation:
Matter is defined as anything that has mass and takes up space. Matter is basically liquid soilds and gasses!
(I hope this helps :>)
What's the enthalpy of neutralization and explain briefly how it relates to esterification
Answer:
The enthalpy of neutralization and its relation to esterification is explained below in details.
Explanation:
The conventional enthalpy variation of neutralization is the enthalpy exchange when extracts of an acid and an alkali respond together under conventional circumstances to generate 1 mole of water. Remark that the enthalpy change of neutralization is always estimated per mole of water produced.
trachea
Meaning of trachea
Answer:
The trachea, also called the windpipe, is a cartilaginous tube that connects the larynx to the bronchi of the lungs, allowing the passage of air, and so is present in almost all air-breathing animals with lungs. The trachea extends from the larynx and branches into the two primary bronchi. At the top of the trachea the cricoid cartilage attaches it to the larynx. The trachea is formed by a number of horseshoe-shaped rings, joined together vertically by ligaments over their substance and by the trachealis muscle at their ends. The epiglottis closes the opening to the larynx during swallowing.
Explanation:
You asked I answered.
Hope this helped! :)
P.S. If you still don't get where the trachea is, look at the graph below. :)
NEED HELP PLZ ASAP!!!!!
A precipitate of lead chloride is formed when silver chloride is dissolved in a saturated solution of lead chloride due to g
Answer:
Due to "Common ion effect".
Explanation:
Lead chloride and Silver chloride have an ion in common which is Cl-, when these two solutions are dissolved, more chloride reacts with lead which shifts equilibrium position to the right hence precipitating out.
Look at the following chemical equation.
10Ag + S = 8Ag S
What is true about this chemical equation? (Hint: The reactant is the substance at the start of a chemical reaction.
The product is the substance at the end of the chemical reaction.
A.It is unbalanced because the number of reactants is less than the number of products.
IB.t is balanced because the products contain the same number of sulfur (S) atoms as the reactants.
C.It is balanced because the mass of the reactants is equal to the mass of the products.
D.It is unbalanced because the products contain fewer silver (Ag) atoms than the reactants.
Answer: I think it is D
Explanation:
SOMEBODY ONCE TOLD ME THE WORLD WAS GONNA ROLL ME
I AIN'T THE SHARPEST TOOL IN THE SHED~
SHE WAS LOOKING KINDA DUM WITH HER FINGER AND HER THUMB
IN THE SHAPE OF AN "L" ON HER FOREHEAD~
WELL THE YEARS START COMING AND THEY DON'T STOP COMING
FED TO THE RULES AND I HIT THE GROUND RUNNING
DIDN'T MAKE SENSE NOT TO LIVE FOR FUN
YOUR BRAIN GETS SMART BUT YOUR HEAD GETS DUM
SO MUCH TO DO, SO MUCH TO SEE--
SO WHATS WRONG WITH TAKING THE BACKSTREETS?
YOU'LL NEVER KNOW IF YOU DON'T GO
YOU'LL NEVER SHINE IF YOU DON'T GLOW!
Answer:
Hey now, you're an all-star, get your game on, go playHey now, you're a rock star, get the show on, get paidAnd all that glitters is goldOnly shooting stars break the moldIt's a cool place and they say it gets colderYou're bundled up now, wait 'til you get olderBut the meteor men beg to differJudging by the hole in the satellite pictureThe ice we skate is getting pretty thinThe water's getting warm so you might as well swimMy world's on fire, how about yours?That's the way I like it and I'll never get boredHey now, you're an all-star, get your game on, go playHey now, you're a rock star, get the show on, get paidAll that glitters is goldOnly shooting stars break the moldAll aboard Ha ha ha ha ha ha ha
Ay, ay, ay, ay, ay, ay, ay
Crazy, but that's how it goes
Millions of people living as foes
Maybe it's not too late
To learn how to love
And forget how to hate
Mental wounds not healing
Life's a bitter shame
I'm going off the rails on a crazy train
I'm going off the rails on a crazy train
Let's go
I've listened to preachers
I've listened to fools
I've watched all the dropouts
Who make their own rules
One person conditioned to rule and control
The media sells it, and you live the role
Mental wounds still screaming
Driving me insane
I'm going off the rails on a crazy train
I'm going off the rails on a crazy train
I know that things are going wrong for me
You gotta listen to my words, yeah
I NEED TO KNOW THIS ASAP
Answer:
I think that the answers A, not 100% sure tho
Explanation:
Because the problem says "highly radioactive" chemicals and gamma rays are highly radioactive chemicals, and gamma rays are very penetrating to the human body
Write out the electron configurations of the ions below and determine which one is listed with an incorrect charge. (the numbers and charges written after the elemental symbol should be understood as superscripts)
A. I-
B.O2+
C. Al3+
D. Mg2+
E. none of the above
Answer:
I think B. O2+
Explanation:
Answer:
B
it must be O2- not O2+, because it's an anion not a cation.
How does Gas Trapping bottles Monitor Volcanos?
( put in your own words don’t look up on internet )
I will give brainlst If you answer correctly.
Answer: the pressure releases gas. The two most abundant gases are sulfur dioxide and carbon dioxide, and if levels of these gases increase,
Explanation:
Flicks tongue stuck to the floor Porter he was triple dog dare to do it if the teacher Miss shields calls for help in the firetruck 0 mph to 42 mph in six seconds what is a fire trucks acceleration?
HELP DUE MONDAY!!!
Answer:
3.128 m/s^2
Explanation:
Acceleration is the change in velocity over the change in time. Final velocity is 42 mph and initial velocity is 0 mph, but we need to convert these values to meters per second (m/s).
To do that, we divide 42 by 2.237 and the result is 18.77.
Now we can calculate the change in velocity: 18.77 - 0 = 18.77 m/s.
Now we need the change in time: 6 s is the elapsed time, 0 s in the starting time. So 6 s - 0 s = 6 s.
Now we divide 18.77 by 6 s and obtain the answer, which is:
18.77 m/s ÷ 6 s = 3.128 m/s^2
as we go down a group
the number of valence electrons?
a Increases
b Decreases
C Remains the same
d None of the above
Answer:
Number of valence electrons stays the same
remains the same
it remains teh same
what is the balanced equation for naphthalene and sulphur?
napthalene: C10H8 sulphur: S02
Explanation:
C10H8
Which force acts on falling objects to oppose gravity?
pull
terminal velocity
air resistance
acceleration
Answer:pull
Explanation:
Jill is recovering from the Flu. At lunchtime, she shares her water bottle with her friend Dara. The next day,
Dara is sick. Which type of Disease is the Flu
Answer: I think its a virus
Explanation: Viruses spread form person to person just like any virus so if I'm correct the disease is a virus
URGENT!!!
5. As the water temperature is increased
from 20°C to 90°C, how many more grams
of copper sulfate will dissolve in 100 grams
of water?
____g
Answer:
40
Explanation:
A piece of dry ice at -76°C begins to sublimate (solid to
gas) when placed at the counter at room temperature. How
many bars are in the final phase energy (Eph)?
Answer:
D
Explanation:
4 bars
HELP ME DUE IN 5 MINUTES I WILL GIVE BRAINLIEST
Most people understand that resources need to be conserved. For example, when brushing your teeth, you conserve water by turning it off until you need it again. Energy within a system follows the Law of Conservation of Energy, so what does the Law of Conservation of Energy mean?
Group of answer choices
Energy can be transformed and destroyed.
Energy cannot be destroyed or created.
Energy cannot be transferred or used up.
Energy can be lost or made.
Answer:
Energy cannot be destroyed or created.
C. i know this is right
Explanation:
if you aint stephanie dont anwer
Answer:
wsp
Explanation:
If you were to add glucose to catalase instead of hydrogen peroxide, would bubbles be produced?
Answer:
No, bubbles would not be produced.
Explanation:
Catalase is an enzyme that catalyses the decomposition of hydrogen peroxide into water (H2O) and oxygen gas (O2). Since oxygen (O2) is a gas, it is physically noticeable as BUBBLES. However, catalase as an enzyme is substrate-specific i.e. it solely acts/breaks down on hydrogen peroxide.
Hence, If one were to add glucose to catalase instead of hydrogen peroxide, oxygen gas observed as BUBBLES will not be produced because catalase will not act on glucose.
just write a C.E.R (claim, evidence, reasoning)
Answer:
I have attached pictures below. Maybe those will help?
Explanation:
Answer:
this is a CER model i did for science
Explanation:
claim : Tissue engineering is good for the future and has a positive impact on the future because tissue engineering restores aged, damaged or lost tissues/organs with artificial tissues in a way past medicines or technology has not.
evidence: The infographic states, “This science field provides opportunities for helping many people replace dead or injured organs with new ones. In doing so, it will give them a healthier, more productive life. This field is just beginning, and it is sure to change the length and quality of life of many people in the future.“
reasoning: Many people can benefit from tissue engineering because they can have dead or injured organs replaced with new ones. Tissue engineering is just the beginning and is still being conducted and tested , but as technology gets more advanced and advanced, tissue engineering will improve peoples lives the way medicines and past technology has never done.
The density of a gas is 1.26 g/L at STP. What is the mass of 1 mole? What could this gas be?
Answer: Molar mass=28.224g/mol, The gas could be Nitrogen gas
Explanation:
Density is calculated as Molar mass/ Molar Volume
Recall that
One mole of an ideal gas at (STP) standard temperature and pressure = 22.4 liters (in Volume)
Given That Density =1.26 g/L
Volume = 22.4L at STP,
Molar mass = Density x Molar Volume
= 1.26 g/L x 22.4L =28.224g
Therefore, if 1 mole of this gas has a mass of 28.224g then its molar mass is equal to 28.224g/mol
The molar mass of Nitrogen = 28.014 g/moL, so we can conclude the the gas could be Nitrogen
The Earth's hours is it spinning on its axis, and it takes 24
Answer:
yes? is there a question...
Explanation:
Answer:
24 hours
Explanation:
Earth spins on its axis once in every 24-hour day. At Earth's equator, the speed of Earth's spin is about 1,000 miles per hour (1,600 km per hour).