Answer:
1. Draw only the valence electrons.
2. Give every element main group element (except hydrogen) an octet of electrons.
3. Give each hydrogen two electrons.
Explanation:
Lewis structures are used to describe the arrangement or configurations of the valence electrons of molecules and polyatomic ions involved in electronic bonding. A Lewis structure consists of the symbols of the elements in the molecule surrounded by dots with each dot representing each of the elements valence electrons. Also, the electrons shared between two elements are shown by dots between the two elements and these electrons are known as shared electron pairs. The valence electrons on atom that is not involved in bonding is known as lone pairs.
The three general rules for drawing Lewis structures are:
1. Draw only the valence electrons. Only the valence electrons of the atoms of elements are shown since they are the only electrons involved in chemical bonding.
2. Give every element main group element (except hydrogen) an octet of electrons. The complete eight valence electrons of the noble gases is associated with their stability. Thus, the main group elements show a tendency to form enough bonds to obtain eight valence electronsmin order to achieve stability. This is known as the octet rule. However, since the maximum number of valence electrons for elements in the first period of the period table is two, the noble gas helium has completely-filled valence shell containing two electrons known as a duplet. Hydrogen belongs to the first period and is therefore an exception tomthe octet rule.
3. Give each hydrogen two electrons. Hydrogen attains a duplet structure in accordance with the structure of helium
What is the purpose of the scientific method?
Answer:
C. To remove any source of bias in an experience
During a chemical reaction, an iron atom became the ion Fe2+. What happened to the iron atom?
Explanation:
Iron atom is been oxidised as it losses 2 electron to form 2 + ion.
Which of the following can be mixed in solution with NH3 to make a buffer?
Answer:
c. NaOH
Explanation:
just took the quiz
Which tasks can be used to start a descriptive investigation
Answer:
The tasks which form the preliminaries to a descriptive investigation are: Making careful objective observations. Asking the relevant scientific questions.
What kind of magma produce the most violent eruptions
Answer:
Explosive eruptions from Composite or strato volcano
Explanation:
since they have multiple holes of exit, they can get pretty explosive.
The molecular formula of water is H, O. What does it express
Answer:
Firstly, the molecular formula of water would be H2O. Secondly, it expresses the amount of different atoms in the water molecule. In this case, H2 would be two Hydrogen atoms, and O would be 1 Oxygen atom.
Explanation:
Hope this helped!
Answer:
It basically means that water contains 2 atoms of Hydrogen and 1 atom of Oxygen.
It also expresses that the valency of Oxygen is 2 and water has more Hydrogen than OxygenIdentify the isoelectronic elements.
i. Cl-, F-, Br-, I-, At-
ii. Ne, Ar, Kr, Xe, He
iii. N3-, S2-, Br-, Cs+, Sr2+
iv. N3-, O2-, F-, Na+, Mg2+
v. Li+, Na+, K+, Rb+,Cs+
Answer:
iv. N³⁻, O²⁻, F⁻, Na⁺, Mg²⁺
Explanation:
Isoelectronic elements are those that have the same number of electrons. So, if at least 2 elements differ in their number of electrons, the series is not of isoelectronic elements.
To know the number of electrons we will consider the atomic number and add electrons if it is an anion and subtract electrons it is a cation.
Identify the isoelectronic elements.
i. Cl⁻, F⁻, Br⁻, I⁻, At⁻. NO. Cl⁻ has 18 electrons (17+1) and F⁻ has 10 electrons (9+1). ii. Ne, Ar, Kr, Xe, He. NO. Ne has 10 electrons and Ar has 18. iii. N³⁻, S²⁻, Br⁻, Cs⁺, Sr²⁺. NO. N³⁻ has 10 electrons (7+3) and S²⁻ has 18 (16+2).iv. N³⁻, O²⁻, F⁻, Na⁺, Mg²⁺. YES. They all have 10 electrons v. Li⁺, Na⁺, K⁺, Rb⁺, Cs⁺. NO. Li⁺ has 2 electrons (3-1) and Na⁺ has 10 (11-1).What would you use to measure
to measure an amount of solid sodium chloride(NaCI)
crystals to add to a 30 mL solution?
A. Triple Beam Balance that measures to the nearest 0.1 grams.
) B. 10 ml graduated cylinder.
Scale that can weigh up to 250 lbs.
D. Spectrophotometer that measures between 100 and 900 nanometers.
please answer all if you can!
Answer:1.b 2.A (i think it might be c) 3 (i have no clue) 4.(no clue) Sorry i only got 1 and 2 witch i think are right its been a while sense i have done this....
Explanation:
Answer this please t
Lol
Answer: trial b
Explanation:
describe how lyophobic sols are synthesize by dispersion method
Explanation:
For preparing lyophobic sol, the substance in bulk is broken down into particles of colloidal dimensions (Dispersion) or aggregating smaller particles into particles of colloidal dimensions (condensation).
If you keep adding sugar to water and there comes a point that you cannot dissolve any more sugar to it then this is called
Answer:
.
Explanation:
Someone help me fill this out TY
Please fill it out in each blank :)
Answer and Explanation:
We have to identify the anion (negatively charged ion) and the positive ion to form each compound. The sum of the positive and negative charges will be equal to 0 for a neutral compound.
Chloride: the anion is Cl⁻ (1 negative charge).
Magnesium (Mg²⁺) + Chloride (Cl⁻) : MgCl₂
Sodium (Na⁺) + Chloride (Cl-): NaCl
Zinc (Zn²⁺) + Chloride (Cl-): ZnCl₂
Lithium (Li⁺) + Chloride (Cl-) : LiCl
Lead(II) (Pb²⁺) + Chloride (Cl⁻): PbCl₂
Calcium (Ca²⁺) + Chloride (Cl⁻): CaCl₂
Iron(II) (Fe²⁺) + Chloride (Cl⁻): FeCl₂
Iron(III) (Fe³⁺) + Chloride (Cl⁻): FeCl₃
Potassium (K⁺) + Chloride (Cl): KCl
Nitrate: the anion is NO₃⁻ (1 negative charge).
Magnesium (Mg²⁺) + Nitrate (NO₃⁻) : Mg(NO₃)₂
Sodium (Na⁺) + Nitrate (NO₃⁻): NaNO₃
Zinc (Zn²⁺) + Nitrate (NO₃⁻): Zn(NO₃)₂
Lithium (Li⁺) + Nitrate (NO₃⁻) : LiNO₃
Lead(II) (Pb²⁺) + Nitrate (NO₃⁻): Pb(NO₃)₂
Calcium (Ca²⁺) + Nitrate (NO₃⁻): Ca(NO₃)₂
Iron(II) (Fe²⁺) + Nitrate (NO₃⁻): Fe(NO₃)₂
Iron(III) (Fe³⁺) + Nitrate (NO₃⁻): Fe(NO₃)₃
Potassium (K⁺) + Nitrate (NO₃⁻): KNO₃
Sulphate: SO₄²⁻ (2 negative charges)
Magnesium (Mg²⁺) + Sulphate (SO₄²⁻) : MgSO₄
Sodium (Na⁺) + Sulphate (SO₄²⁻): Na₂SO₄
Zinc (Zn²⁺) + Sulphate (SO₄²⁻): ZnSO₄
Lithium (Li⁺) + Sulphate (SO₄²⁻) : Li₂SO₄
Lead(II) (Pb²⁺) + Sulphate (SO₄²⁻): PbSO₄
Calcium (Ca²⁺) + Sulphate (SO₄²⁻): CaSO₄
Iron(II) (Fe²⁺) + Sulphate (SO₄²⁻): FeSO₄
Iron(III) (Fe³⁺) + Sulphate (SO₄²⁻): Fe₂(SO₄)₃
Potassium (K⁺) + Sulphate (SO₄²⁻): K₂SO₄
Carbonate: CO₃²⁻ (2 negative charges)
Magnesium (Mg²⁺) + Carbonate (CO₃²⁻) : MgCO₃
Sodium (Na⁺) + Carbonate (CO₃²⁻): Na₂CO₃
Zinc (Zn²⁺) + Carbonate (CO₃²⁻): ZnCO₃
Lithium (Li⁺) + Carbonate (CO₃²⁻): Li₂CO₃
Lead(II) (Pb²⁺) + Carbonate (CO₃²⁻): PbCO₃
Calcium (Ca²⁺) + Carbonate (CO₃²⁻): CaCO₃
Iron(II) (Fe²⁺) + Carbonate (CO₃²⁻): FeCO₃
Iron(III) (Fe³⁺) + Carbonate (CO₃²⁻): Fe₂(CO₃)₃
Potassium (K⁺) + Carbonate (CO₃²⁻): K₂CO₃
Hydroxide: OH⁻ (1 negative charge)
Magnesium (Mg²⁺) + Hydroxide (OH⁻): Mg(OH)₂
Sodium (Na⁺) + Hydroxide (OH⁻): NaOH
Zinc (Zn²⁺) + Hydroxide (OH⁻): Zn(OH)₂
Lithium (Li⁺) + Hydroxide (OH⁻): LiOH
Lead(II) (Pb²⁺) + Hydroxide (OH⁻): Pb(OH)₂
Calcium (Ca²⁺) + Hydroxide (OH⁻): Ca(OH)₂
Iron(II) (Fe²⁺) + Hydroxide (OH⁻): Fe(OH)₂
Iron(III) (Fe³⁺) + Hydroxide (OH⁻): Fe(OH)₃
Potassium (K⁺) + Hydroxide (OH⁻): KOH
Phosphate: PO₄³⁻ (3 negative charges)
Magnesium (Mg²⁺) + Phosphate (PO₄³⁻): Mg₃(PO₄)₂
Sodium (Na⁺) + Phosphate (PO₄³⁻): Na₃PO₄
Zinc (Zn²⁺) + Phosphate (PO₄³⁻): Zn₃(PO₄)₂
Lithium (Li⁺) + Phosphate (PO₄³⁻): Li₃PO₄
Lead(II) (Pb²⁺) + Phosphate (PO₄³⁻): Pb₃(PO₄)₂
Calcium (Ca²⁺) + Phosphate (PO₄³⁻): Ca₃(PO₄)₂
Iron(II) (Fe²⁺) + Phosphate (PO₄³⁻): Fe₃(PO₄)₂
Iron(III) (Fe³⁺) + Phosphate (PO₄³⁻): FePO₄
Potassium (K⁺) + Phosphate (PO₄³⁻): K₃PO₄
A barium hydroxide solution is prepared by dissolving 2.29 g of Ba(OH)2 in water to make 46.6 mL of solution. What is the concentration of the solution in units of molarity?
Concentration: 0.287 M
The barium hydroxide solution is used to titrate a perchloric acid solution of unknown concentration. Write a balanced chemical equation to represent the reaction between barium hydroxide and perchloric acid.
Chemical Equation:
If 25.5 mL of the barium hydroxide solution was needed to neutralize a 8.99 mL aliquot of the perchloric acid solution, what is the concentration of the acid?
Concentration:
Answer:
0.287 M
Ba(OH)₂ + 2 HClO₄ ⇒ Ba(ClO₄)₂ + 2 H₂O
1.62 M
Explanation:
Step 1: Calculate the concentration of Ba(OH)₂
We will use the following expression.
[Ba(OH)₂] = mass Ba(OH)₂/ molar mass Ba(OH)₂ × liters of solution
[Ba(OH)₂] = 2.29 g/ 171.34 g/mol × 0.0466 L = 0.287 M
Step 2: Write the balanced neutralization equation
Ba(OH)₂ + 2 HClO₄ ⇒ Ba(ClO₄)₂ + 2 H₂O
Step 3: Calculate the reacting moles of Ba(OH)₂
25.5 mL of 0.287 M Ba(OH)₂ react.
0.0255 L × 0.287 mol/L = 7.32 × 10⁻³ mol
Step 4: Calculate the reacting moles of HClO₄
7.32 × 10⁻³ mol Ba(OH)₂ 2 mol HClO₄/1 mol Ba(OH)₂ = 0.0146 mol HClO₄
Step 5: Calculate the concentration of HClO₄
0.0146 moles of HClO₄ are in 8.99 mL of solution.
[HClO₄] = 0.0146 mol/0.00899 L = 1.62 M
Why can characteristics properties be used to identify unknown substances
Characteristic properties are used because the sample size and the shape of the substance does not matter.
Suppose you are trying to separate three Proteins using Gel-Filtration chromatography. The sizes of each are given below:
Protein A: 1200 kDa
Protein B: 2000 kDa
Protein C: 800 kDa
Which protein will be the first to emerge from the column?
Answer: The correct answer is Protein B.
Explanation:
Gel-filtration chromatography is a separation technique that is based on the size of the molecules in a compound. It is also known as size-exclusion chromatography in which the eluent (carrier) used is an aqueous solution.
The matrix that is used is a porous material. When the sample is inserted in the column, the smaller particles interact strongly with the matrix than the large ones. Thus, as the eluent is passed through the matrix, larger molecules come out first, and the smallest molecule comes out last.
Given sizes of the proteins:
Protein A: 1200 kDa
Protein B: 2000 kDa
Protein C: 800 kDa
As protein B has the largest size of all the given proteins, it will emerge out first from the column.
Hence, the correct answer is Protein B.
Select all the correct images.
Select the atoms that belong to the same element.
16 protons 16 neutrons
16 electrons
11 protons 10 neutrons 11 electron
13 protons 14 neutrons 13 electrons
Answer:
11 protons 10 neutrons 11 electron
13 protons 14 neutrons 13 electrons
Explanation:
Isotopes are atoms of the same element having same atomic number but different mass numbers.
how many moles of neon gas have a volume of 0.84 L and a pressure of 4.6 atm at 222k
Answer:
n = 0.21 moles
Explanation:
Given that,
Volume, V = 0.84 L
Pressure, P = 4.6 atm
T = 222 K
We need to find the number of moles of Neon gas. We know that,
PV = nRT
Where
n is the number of moles
R i the gas constant, R = 0.08206 L-atm/mol-K
Put all the values,
[tex]n=\dfrac{PV}{RT}\\\\n=\dfrac{4.6\times 0.84}{0.08206 \times 222}\\\\n=0.21\ \text{moles}[/tex]
So, there are 0.21 moles of Neon gas.
There are four different starting molecules that one might use to synthesize the illustrated alkyl halide as the major product using an electrophilic addition reaction. Please draw all four of them.
Answer:
Explanation:
An electrophilic addition reaction occurs when an electrophile attacks a substrate, with the end result being the inclusion of one or many comparatively straightforward molecules along with multiple bonds.
In the given question, the hydrogen bromide provides the electrophile while the bromide is the nucleophile. The mechanism proceeds with the attack of the electrophile on the carbon, followed by deprotonation. This process is continued with a formation of carbocation and the bromide(nucleophile) finally bonds to the carbocation to form a stable product.
The first diagram showcases the possible various starting molecules for the synthesis while the second diagram illustrates their mechanism.
Water is considered to be a diatomic molecule because it composed of two different atoms. True or false?
Answer:
false
Explanation:
False, water is a polyatomic molecule made up of two atoms of oxygen and 1 atom of hydrogen.
Explanation:
The monoatomic molecule is composed of a single atom of an element.For example: Helium(He) , argon(Ar) etc.The diatomic molecule is composed of two atoms of the same or different elements.For example: hydrochloric acid (HCl), sodium chloride (NaCl) etc.The polyatomic molecule is composed of three or more than three atoms of the same or different elements.For example: water ([tex]H_2O[/tex]), sodium hydroxide(NaOH) etc.So, from this, we can conclude that water is a polyatomic molecule made up of two atoms of oxygen and 1 atom of hydrogen.
Learn more about types of molecules here:
brainly.com/question/3213630?referrer=searchResults
brainly.com/question/4979095?referrer=searchResults
An object with a mass of 0.255 kg and density of 2.89 g/cm^3 measures 34 mm in length and 46 mm in width. What is the height of the object?
1) 5.6 cm
2) 5.6•10^-2 cm
3) 7.2 •10^-4 cm
5.64 I think, I'm sorry if I'm wrong
what would be the mass of 44.8 L of CO2 gas at STP?
show work if possible
Answer:
[tex]m=88.02g[/tex]
Explanation:
Hello there!
In this case, for this ideal gas law problem, it turns out necessary for us to remember that one mole of any gas is contained in 22.4 L at STP and therefore, we can use the following ratio to calculate the moles in 44.8 L of CO2:
[tex]\frac{1mol}{22.4L} =\frac{x}{44.8L}\\\\x= \frac{1mol*44.8L}{22.4L}=2mol[/tex]
Finally, since the molar mass of CO2 is 44.01 g/mol, we calculate the mass as follows:
[tex]m=2mol*\frac{44.01g}{1mol}\\\\m=88.02g[/tex]
Regards!
Soda contains phosphoric acid (H3PO4). To determine the concentration of phosphoric acid in 50.0 mL of soda, the available phosphate ions are precipitated with excess silver nitrate as silver phosphate (418.58 g/mol). The dry Ag3PO4 is found to have a mass of 0.0576 g. What is the concentration of phosphoric acid in the soda?
Answer:
0.0270w/v% H3PO4 in the soda
Explanation:
All phosphates reacts producing Ag3PO4. To solve this question we must convert the mass of Ag3PO4 to moles. These moles = moles of H3PO4. We can find, thus, the mass of H3PO4 and the w/v% as follows:
Moles Ag3PO4 -Molar mass: 418.58g/mol-
0.0576g * (1mol / 418.58g) = 1.376x10⁻⁴ moles Ag3PO4 = moles H3PO4
Mass H3PO4 -Molar mass: 97.994g/mol-
1.376x10⁻⁴ moles Ag3PO4 = moles H3PO4 * (97.994g/mol) = 0.0135g H3PO4
w/v%:
0.0135g H3PO4 / 50.0mL * 100 =
0.0270w/v% H3PO4 in the sodaA certain first-order reaction is 27.5 percent complete in 8.90 min at 25°C. What is its rate constant?
Answer:
[tex]k= 0.145min^{-1}[/tex]
Explanation:
Hello there!
In this case, according to the given information, it turns out necessary for us remember that the first-order kinetics is given by:
[tex]ln(A/A_0)=-kt[/tex]
Whereas the 27.5% complete means A/Ao=0.275, and thus, we solve for the rate constant as follows:
[tex]k=\frac{ln(A/A_0)}{-t}[/tex]
Then, we plug in the variables to obtain:
[tex]k=\frac{ln(0.275)}{-8.90min}\\\\k= 0.145min^{-1}[/tex]
Regards!
Unknown A melts at 113- 114oC. Known compounds 3-Nitroaniline and 4-Nitrophenol both melt at 112-114 oC. If A is mixed with 3-Nitroaniline and the melting point becomes broad and depressed, what must A be __________A) 3-Nitroaniline B) 4-Nitrophenol C) Both
Answer:
C) Both
Explanation:
Whenever we mix any pure form of a compound with some other form of a compound which is not in the other standard pure state, this results in the melting point of mixture to get dispersed and it becomes broad form.
Thus, when a known compound of 3-Nitroaniline mixes with both 3-Nitroaniline and 4-Nitrophenol, the melting point of the compound becomes depressed and board.
Thus the correct option is (C).
Sodium is a highly reactive metal and
chlorine is a toxic gas, but when they
come together the resulting material,
sodium chloride, is essential for life.
Which of the following is true when
sodium and chlorine are brought into
contact with one another?
Answer:
NaCl
Explanation:
[tex]na + cl > nacl[/tex]
This is also a salt
Project: Global Temperature Change
Research and write an essay about the rise of global temperatures over the past century.
PLEASE HELP THIS IS 10% OF MY GRADE
Answer:
Im sorry i cant write a whole essay right now but these sourcea could help.
https://climate.nasa.gov/effects/
https://www.climate.gov/news-features/understanding-climate/climate-change-global-temperature
Answer:
have you done it yet?
Explanation:
..
HELLP I NEEED HELP NOWW NO GUESSING FRFR
What will happen when a piece of magnesium metal is dropped into a beaker
containing a 1 M solution of copper(II) chloride?
Mg2+ + 2e → Mg(s) ° =- 2.37 V
Cu2+ + 2e → Cu(s) £° = + 0.34 V
How can you identify ethane from ethene
does light appears to travel in straight lines. travelling from light sources until it hits the surface of an object?? (Truer or False) if your answer is true then what is the reason why does light appears to travel in straight lines??.
Answer:
true once light has been produce it will keep travelling jn straight parts until it hits something else
