Answer:
0.8910 mols of NaOH in a 35.65 g sample of NaOH
Explanation:
Mass off NaOH = 39.997
given = 35.65 g of NaOH
35.65 g of NaOH * 1 mol NaOH = 0.8910, since there are 4 sig figs.
/40.01 g
A 35.65 g sample of NaOH contains 0.8910 moles of NaOH.
What is mole?The mole, denoted by the sign "mol," is the volume of a system that has the same number of atoms in 0.012 kilograms of carbon-12 as there are elementary particles.
The mole, often known as mol, is a SI unit used to measure how many particles are present in a given substance. A mole is made up of 6.02214179 atoms or other fundamental building blocks like molecules.
Mass off NaOH = 39.997
given = 35.65 g of NaOH
No of moles of NaOH =35.65 g of NaOH × 1 mol NaOH /40.01 g
No of moles of NaOH = 0.8910 moles.
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Find the element. Plz help!
Answer:
Hydrogen.
Explanation:
We see in the nucleus that we have 1 proton and 1 neutron.
The number of protons in the nucleus determines which element it is.
Element with 1 proton is the 1st element on the Periodic Table, Hydrogen.
Write a complete, balanced chemical equation where tin metal reacts with aqueous hydrochloric acid to produce tin(II) chloride and hydrogen gas. Include states.
From the equation, which element is oxidized, and which element is reduced?
Answer:
Zn(s)+2HCl(aq)→ZnCl2(aq)+H2(g)
Explanation:
The net reaction is Z n ( s ) + 2 H + ( a q ) → Z n 2 + ( a q ) + H 2 ( g ) The C l − ions are spectators - they don't change.
The mass spectrum of the element Sb is most likely represented by which of the following?
A. 122 Atomic Mass
B. 121 and 123 Atomic Mass
C. 120, 123 and 124 Atomic Mass
D. 120,121 and 124 Atomic Mass
The correct answer is B: 121 and 123 Atomic Mass.
Mass spectrometers only detect stable isotopes.
Almost all elements exhibit isotopy. Isotopy is a phenomenon whereby atoms of the same atomic number have different atomic masses. The relative atomic mass of each element is the weighted average of the masses of all its isotopes.
Owing to the phenomenon of isotopy, the relative atomic mass of elements are not whole numbers.
The isotopes recorded by a mass spectrometer are stable isotopes of an element. The two stable isotopes of antimony are Sb-121 and Sb-123. These two appear in its mass spectrum.
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Why do nonmetals have a higher electronegativity?
Answer:
Nonmetals have more valence electrons and increase their stability by gaining electrons to become anions.
Answer: Because they are on the father side of the periodic table
Explanation: Electronegativity increases as you move from left to right on the periodic table
Julio eats a taco for dinner. What represents a physical change in the taco?
A) saliva changing the starch in the crust to sugar
B) teeth tearing off a bite of a taco
C) chemicals in the stomach digesting proteins
D) breaking down of fats in the taco by bile
The physical change is a modification in the structure of the chemical substance. Teeth tearing off a bite of a taco represents a physical change. Thus, option B is correct.
What is a physical change?A physical change is an alteration in the structure of the chemical involved in the substance. In a physical change, the composition of the chemical remains intact and does not change. It includes changes in texture, temperature, shape, and phase of matter.
The processes like dissolving, boiling, cutting, melting, bending, and freezing are said to be physical changes. The teeth-bitting tacos result in smaller bites is a physical change as there is a change in the shape and size but not the composition.
Therefore, option B. the teeth tearing tacos is an example of physical change.
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Is a single piece of evidence enough to show that a hypothesis is not supported?
Answer:
no
Explanation:
During STATIC ELECTRICITY to what type of objects & direction do electrons ALWAYS move to?
In a chemical formula what is used to indicate the number of atoms of each element
Answer:
molecular number
Explanation:
because it shows exact numbers
water is always subject to the law of
Answer:
motion
Explanation:
i just know things
Which element’s symbol could replace the question mark in the diagram?
boron (B)
neon (Ne)
rubidium (Rb)
arsenic (As)
Answer:
D- Arsenic (As)
don’t fail pls :) ✨
The Arsenic (As) element's symbol could replace the question mark in the diagram. Therefore, option D is correct.
What is an electron dot diagram?An electron dot diagram is a diagram used to represent the valence electrons of an atom in a simple way. Valence electrons are the electrons in the outermost shell of an atom, which are involved in chemical bonding.
In an electron dot diagram, the symbol of the element is used to represent the nucleus and inner electrons of the atom, and dots are placed around the symbol to represent the valence electrons. Each dot represents one valence electron, and the dots are placed on each of the four sides of the symbol (top, bottom, left, and right) before doubling up.
Thus, the Arsenic (As) element's symbol could replace the question mark in the diagram. Therefore, option D is correct.
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Your question is incomplete, most probably the full question is this:
Which element’s symbol could replace the question mark in the diagram?
boron (B)
neon (Ne)
rubidium (Rb)
arsenic (As)
An ionic bond occurs between a ___ and ___
Answer:
An ionic bond occurs between two opposite charges are attracted
Explanation: Two opposite charges are attracted to each other
Show all work: A metal bar has a length of 5.0 cm, a width of 3.0 cm, and a height of 1.0 cm. What volume of water, measured in deciliters, would this bar displace?
15 cm
and I have to explain but there's nothing to explain so yea
HELP PLEASE
Chemical name for As2S3
Answer:
Chemical name for As2S3 is Arsenic sulfide
Explanation:
Answer:
Arsenic Sulfide
Explanation:
Find the average atomic mass of smithium ?
Answer:
google friend tell me
Explanation:
You will have to look up the isotopic distribution of lithium nuclei. ALL lithium nuclei have 3 positively charged nuclear particles, protons, i.e. Z = 3 . These 3 particles give rise to the element's identity. If you take the weighted average of ALL lithium nuclei, we get an average mass of 6.941 g⋅mol−1
what are class C fire extinguishers used for
Predict the charge on the monatomic ions formed from the following atoms in binary ionic compounds:
(a) I
(b) Sr
(c) K
(d) N
(e) S
(f) In
An ionic bond would form between which pairs of elements? atomic number 4 and atomic number 18 atomic number 7 and atomic number 8 atomic number 3 and atomic number 4 atomic number 8 and atomic number 12
Answer:
atomic number 8 and atomic number 12
Explanation:
atomic number 8 and atomic number 12 , element with the atomic number 8 is oxygen, and the element with atomic number 12 is Magnesium
Magnesium has low ionization energy, hence higher tendency to loose its two outermost electrons to form positive ion.
Oxygen has high electron affinity, hence higher tendency to accept or gain electrons to form negative ion.
The electronegativity difference between the element with atomic number 8 and element with atomic number 12 is greater for the formation of ionic bond
There are two types of chemical compound one is covalent compound and other is ionic compound, covalent compound formed by sharing of electron and ionic compound formed by complete transfer of electron. Therefore, the correct option is option C.
What is chemical Compound?
Chemical Compound is a combination of molecule, Molecule forms by combination of element and element forms by combination of atoms in fixed proportion.
An ionic compound is a metal and nonmetal combined compound. Ionic compound are very hard. They have high melting and boiling point because of strong ion bond.
atomic number 8 =oxygen
atomic number 12= Magnesium
Magnesium has a low ionization energy and so a greater proclivity to lose its two outermost electrons to create a positive ion. Because oxygen has a high electron affinity, it is more likely to accept or acquire electrons to create a negative ion.
Therefore, the correct option is option C.
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Lara’s chemistry teacher has a decorative metal cube on her desk. The underside of the cube indicates that is made of stainless steel. However, Lara thinks it is too heavy to be this metal. She researches the density of stainless steel and finds it is 7.85g/cm³. She carries out this experiment to verify if the cube is actually made of stainless steel.
Answer:
D: 4, 5
Explanation:
what is the significant figures of 12.00
Which of the following is a unit for acceleration?
A) m/s
B) m/s2
C) s/m 2
D) s/m
Which of the following is not a compound? Sulfur, sodium chloride, ammonia, carbon dioxide
Answer:
Carbon monoxide is a colorless, odorless, and tasteless flammable gas that is slightly less dense than air.
Fill in the blank. An answer would be great right now!!! I’m having trouble with science. thanks!!
Answer:
1. Richter 2. Moment
Hope this helps !!
Q5 4.70 g of methanoic acid reacts to form 3.60 g of methanoic
anhydride. The equation for this reaction is:
2HCOOH + (CHO),0 + H2O
Calculate the percentage yield of this reaction.
Answer:
The anwser is always Jesus.
Explanation:
Things can only go downhill from here
Paul's doctor says his cardiorespiratory fitness level is excellent, but she worries about Paul's muscular fitness. Paul enjoys gymnastics, baseball, biking, and yoga. Increasing the frequency of which activity will best improve Paul's muscular fitness? (3 points)
Gymnastics
Baseball
Biking
Yoga
Answer:
Explanation:
Gymnastics
Answer: Gymnastics
On a separate sheet of paper solve the following problem: How many cups are
in 3.5 gallons? (1 gal = 16 cups)
Type your answer...
Answer:
48 cups
Explanation:
16 x 3.5 = 48
Since one gallon is 16 cups, it would be done like this
Why are journal articles important in the spread of scientific knowledge?
Help me pls guy’s
Answer:
When published, each article expands the library of scientific literature available to all scientists and contributes to the overall knowledge base of the discipline of science. They report new research for the first time.
How are covalent molecules named?
A. A number is used in front of each element's name, and the first element is changed to end in -ide.
B. A prefix is added to each element's name, and the second element is changed to end in -ide.
C. A roman numeral is used to indicate the number of atoms of each element.
D. The name of each element is followed by a number to indicate the amount of atoms.
Answer:
A prefix
Explanation:
you're welcome
The covalent molecules named as,
A prefix is added to each element's name, and the second element is changed to end in -ideSo, option B is correct one.
What is covalent molecules?The molecule formed by sharing of electrons between atoms is called covalent molecules .The atoms which form covalent molecules must have similar or less electnegativity difference.Examples of covalent molecules are hydrogen molecule [tex]H_{2}[/tex] ,carbon dioxide, methane etcTo learn more about covalent molecules,
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Helppp. Calcium reacts with bromine to form Calcium bromide
Ca - - - - > Ca+2
Br2 - - - - > 2br
A. Complete the equation by adding electrons
[tex]\mathfrak{\huge{\pink{\underline{\underline{AnSwEr:-}}}}}[/tex]
Actually Welcome to the Concept of the Chemical Bonding.
Since we know that, calcium shares 2 electrons and Bromide being a halogen accepts 1 electron at a time,
So 2 bromides combine together to form a bond with Calcium, so we get as,
Ca2+ + 2Br -----------------------> CaBr2
CaBr2 is the compound formed.
PLEASE ANSWER SOON THIS IS DUE IN LIKE, 5-10 MINS
Which pair have the same electron configuration? You may use the periodic chart
Cl- and Ar
Cl and Ar
Cl- and Ar-
Cl+ and Ar
The half-life of Th-227 is 18.2 day. How many days are required for 0.70g of a given sample
to decay to 0.04375 g?
Answer:
73 days
Explanation:
From the question given above, the following data were obtained:
Half life (t½) = 18.2 day.
Original amount (N₀) = 0.70 g
Amount remaining (N) = 0.04375 g
Time (t) =.?
Next, we shall determine the rate of decay of the isotope. This can be obtained as follow:
Half life (t½) = 18.2 day.
Decay constant (K) =.?
K = 0.693 / t½
K = 0.693 / 18.2
K = 0.038 /day
Finally, we shall determine the time taken for the isotope to decay to 0.04375 g. This can be obtained as follow:
Original amount (N₀) = 0.70 g
Amount remaining (N) = 0.04375 g
Decay constant (K) = 0.038 /day
Time (t) =.?
Log(N₀/N) = kt /2.303
Log (0.70/0.04375) = (0.038 × t) /2.303
Log 16 = (0.038 × t) /2.303
1.2041 = (0.038 × t) /2.303
Cross multiply
1.2041 × 2.303 = 0.038 × t
Divide both side 0.038
t = (1.2041 × 2.303) / 0.038
t = 72.97 ≈ 73 days
Therefore, it will take approximately 73 days for the isotope to decay to 0.04375 g