Question 2 2 points)
Which of the atoms shown has an atomic number of 42
1
2
4
7

Answers

Answer 1

Answer:

4 is the answer

Explanation:

i am not sure for this question


Related Questions

Cal is titrating 50.8 mL of 0.319 M HBr with 0.337 M Ba(OH)2. How many mL of Ba(OH)2 does Cal need to add to reach the equivalence point?

Answers

Answer:

[tex]V_{base}=24.04mL[/tex]

Explanation:

Hello!

In this case, according to the chemical reaction by which HBr reacts with Ba(OH)2:

[tex]2HBr+Ba(OH)_2\rightarrow BaBr_2+2H_2O[/tex]

We can see there is a 2:1 mole ratio between the acid and the base; thus, at the equivalent point we can write:

[tex]2M_{base}V_{base}=M_{acid}V_{acid}[/tex]

Therefore, for is to compute the volume of the used base, we proceed as shown below:

[tex]V_{base}=\frac{M_{acid}V_{acid}}{2M_{base}}[/tex]

And we plug in to obtain:

[tex]V_{base}=\frac{0.319M*50.8mL}{2*0.337M}\\\\V_{base}=24.04mL[/tex]

Best regards!

A low-pressure weather system comes into the city of Denver. The atmospheric pressure is 693 mmHg.693 mmHg. If 78.0%78.0% of dry air is nitrogen, what is the partial pressure of nitrogen in this low-pressure system?

Answers

Answer:

540.54 mmHg

Explanation:

We know that the partial pressure of a substance is defined as; Mole fraction * total pressure.

If the total amount of gases in the atmosphere is 100%, the mole fraction of nitrogen gas is now

78/100 = 0.78

Thus, partial pressure of nitrogen gas = 0.78 * 693 = 540.54 mmHg

What is the source of most of the salt in the oceans?
human activities adds salt into the ocean
O rivers and streams carry sediment containing salt to the ocean
O marine fish produce salt adding it into the ocean
wind blows the salt into the ocean

Answers

Rivers and streams though that’s not the wording I would use

A) Suppose you separate a 3.02 g mixture of sand and salt. You recover 1.43 g of salt and 1.41 g of sand. What is the percent recovery of the mixture?
B) Suppose you separate a 3.02 g mixture of sand and salt. You recover 1.43 g of salt and 1.41 g of sand. What is the percent recovery of the mixture?
C) Calculate the percent by mass of a solution made from 15 g NaCl (the solute) and 69 g water.
D) What percent of 73.0 g is 26.1 g?

Answers

Answer:

A-B) 94 %.

C) 17.9 %.

D) 35.8 %.

Explanation:

Hello!

A-B) In this case, since the total mass of the mixture is 3.02 g and 1.43g+1.41g=2.84 g are recovered in total, we can compute the percent recovery as shown below:

[tex]\%rec=\frac{2.84g}{3.02g}*100\%\\\\\%rec=94\%[/tex]

C) Here, since the solution is made up of NaCl and water, we can say that the mass of the solution is 15g+69g=84g; thus, the percent by mass would be:

[tex]\%=\frac{15g}{84g}*100\%\\\\\%=17.9\%[/tex]

D) In this case, we simply divide 26.1 g by 73.0 g in order to obtain the percent:

[tex]\%=\frac{26.1g}{73.0g}*100\%\\\\\%=35.8\%[/tex]

Best regards!

The percentage in the cases are as follows;

A and B is; 94%C is; 17.9%D is; 35.8%

Questions A and B are similar and can be solved as follows;

The total mass of the mixture is 3.02g.The recovered mass = 1.43g + 1.41g = 2.84g

% recovery = (2.84/3.02) × 100%

% recovery = 94%

Question C can be solved as follows;

Total mass of solution = 15 + 69 = 84gMass of solute = 15g

% by mass = (15/84) × 100%

% by mass = 17.9%

Question D can be solved as follows;

% = (26.1/73) × 100%% = 35.8%

Read more:

https://brainly.com/question/24712879

Heart attacks can cause sudden death.

True

False

Answers

Answer:

True

Explanation:

1

Which Element Am I (Core)

Names

1. I have 4 valence electrons and 2 energy levels. Which element am I?

2. Iam in group 16 with 2 energy levels. Which element am I?

3. I am in Period 2 and belong to the same group (family) as silicon. Which element am 1?

4. I have 7 valence electrons and 3 energy levels? Which elementar ?

5. I am in period 3 and I have 12 protons in my nucleus. Which element am 1?

Berr

Sul

ca

3

6

5

6. I am the only element with no neutrons in my nucleus. Which element am 17

6

7. I am the only metalloid with 3 energy levels. Which element am I?

8. I have 1 valence electron and 11 protons, which element am I?

9. Thave only one energy level that is full. Which element am I?

10.1 have 8 valence electrons and I have 4 energy levels. Which element am 1?

10

Answers

Answer:

1) Helium

2) Oxygen

3)Carbon

4) Chlorine

5) Magnesium

Explanation:

Helium has the electron arrangement 2, 2. There are two electrons in the first shell and two electrons in the second shell.

Oxygen is the first member of group 16, there are two energy levels in oxygen which are 2,6.

Carbon is in period 2 and is the first member of group 14 (the silicon family).

Chlorine has 7 valence electrons, the electrons are arranged as 2, 8, 7.

Magnesium has 12 protons and 12 electrons. It is the second member of period 3.

Which planet has these characteristics? - the only planet to have liquid water on its surface - almost three quarters of its surface is covered in water - has a nearly circular orbit

Answers

well assuming we have all of these, earth

what volume of copper metal is needed to react with 3.5 moles of silver nitrate

Answers

Answer:

3.40 g

Explanation: don't have one :P

The dissociation constant of formic acid and acetic acid are 2.14×10^-4 and 1.81×10^-5 respectively. What is the relative strength of the acids

Answers

Answer: The formic acid is 3.5 times stronger than acetic acid.

Explanation:

The strength of an acid depends on its acid dissociation constant.

For a hypothetical monoprotic acid HA, the dissociation equilibrium is:

[tex]HA\rightleftharpoons H^++A^-[/tex]

[tex]K_a=\frac{[H^+][A^-]}{[HA]}[/tex]

More is the value of [tex]K_a[/tex] , greater is the dissociation and stronger is the acid.

[tex]\frac{Strength_{\text {formic acid}}}{Strength_{\text {acetic acid}}}=\sqrt{\frac{2.14\times 10^{-4}}{1.81\times 10^{-5}}}=3.5[/tex]

Thus formic acid is 3.5 times stronger than acetic acid.

What mass of silver nitrate will be needed to react with 125 grams of magnesium chloride?

Answers

Answer:   m =  4.2 gAgCl

Explanation:  

Can you guys help me explain these? I will mark brainliest to whoever answers it right oh and this is due tommorow so im rushing!

Answers

Answer:

Conduction  

Conduction moves heat through direct sub-atomic crash. A region of more prominent dynamic energy will move nuclear power to a region with lower active energy. Higher-speed particles will crash into more slow speed particles. The more slow speed particles will increment in motor energy subsequently. Conduction is the most widely recognized type of warmth move and happens through actual contact. Models is place your hand against a window or spot metal into an open fire.  

The interaction of warmth conduction relies upon the accompanying components: temperature slope, cross-segment of the material, length of the movement was, and actual material properties. The temperature inclination is the actual amount that portrays the bearing and pace of warmth travel. Temperature stream will consistently happen from most sultry to coldest or, as expressed previously, higher to bring down active energy. Once there's warm harmony between the two temperature contrasts, the warm exchange stops.

Convection  

At the point when a liquid, like air or a fluid, is warmed and afterward ventures from the source, it conveys the nuclear power along. This sort of warmth move is called convection. The liquid over a hot surface grows, turns out to be less thick, and rises.

Radiation

Thermal radiation generates from the emission of electromagnetic waves. These waves carry the energy away from the emitting object. Radiation occurs through a vacuum or any transparent medium (either solid or fluid). Thermal radiation is the direct result of random movements of atoms and molecules in matter. Movement of the charged protons and electrons results in the emission of electromagnetic radiation.

Mass number 107 and 61 neutrons

Answers

An element with a mass number of 107 and 61 neutrons would be {Ag} aka silver

What is the electronegativity and bond polarity like in the "head" vs. the "tail" ends of soap?

Answers

Answer:

gay

Explanation:

very gay

The definition of symbiotic is
O Having tiny tentacles
O consisting of two oxygen atoms
O having a hard external covering
O living in close association

Answers

Answer:

Living in close association

Explanation:

2. How many moles are there in 20 grams of Carbon?

Answers

Answer:

1.6666666666666 is the ans bcz in each mole there r 12 grams of carbon so the ans is goingtobe 20÷12

According to the mole concept, there are 1.66 moles in 20 grams of carbon.

What is a mole?

Mole is defined as the unit of amount of substance . It is the quantity measure of amount of substance of how many elementary particles are present in a given substance.

It is defined as exactly 6.022×10²³ elementary entities. The elementary entity can be a molecule, atom ion depending on the type of substance. Amount of elementary entities in a mole is called as Avogadro's number.

It is widely used in chemistry as a suitable way for expressing amounts of reactants and products.For the practical purposes, mass of one mole of compound in grams is approximately equal to mass of one molecule of compound measured in Daltons. Molar mass has units of gram per mole . In case of molecules, where molar mass  in grams present in one mole  of atoms is its atomic mass.

Number of moles is calculated as, mass/molar mass, thus on substitution , number of moles=20/12=1.66 moles.

Thus, there are 1.66 moles in 20  grams of carbon.

Learn more about moles,here:

https://brainly.com/question/26416088

#SPJ6

Which of these describes a Mole in Chemistry?

A. A counting term for substances
B. The Molar mass of substance in grams
C. 6.02 x 10^23
D. All of the above describe a mole

Answers

Answer: D. All of the above describe a mole

Explanation:

Mole is the unit for amount of substance. It is used for describing large number of particles.

According to avogadro's law, 1 mole of every substance weighs equal to molecular mass and contains avogadro's number [tex]6.023\times 10^{23}[/tex] of particles.

For example: 1 mole of Na atom will weigh 23 grams and contains [tex]6.023\times 10^{23}[/tex] atoms.

Thus all the above describes a mole.

What is the voltage in a circuit is the current is 3 amps and the resistance is 3 ohms

Answers

Answer:

9

Explanation:

V=I*R

3*3

Thats the answer

How will this system at equilibrium be affected by each of the conditions stated here? 2 Upper H Subscript 2 Baseline (g) + Upper O Subscript 2 Baseline (g) double-headed arrow 2 Upper H Subscript 2 Baseline Upper O (g) + heat. removal of H2O addition of O2 decrease in pressure increase in temperature

Answers

Answer:

removal of H2O

✔ System will shift toward the products.

addition of O2      

✔ System will shift toward the products.

decrease in pressure

✔ System will shift toward the reactants.

increase in temperature      

✔ System will shift toward the reactants.

Explanation:

The reaction Equation :

2H₂ (g)  + O₂ (g) ↔ 2H₂O (g) + heat

Answer :

a) Removal of H₂O : The system will move towards the products of the reaction

b) addition of O₂ : The system will move towards the products of the reaction

c) decrease in pressure : The system will tend to move towards the reactants

d) Increase in temperature: The system will tend to move towards the reactants as well

Reason

In an equilibrium reaction changes to reactant components surroundings/conditions in which the reaction is been carried out can cause a significant change in the entire reaction process.

Hence; Removal of H₂O will cause the reaction system to move towards the products also the addition of O₂ will make the equation of the  reaction system move towards the product

Decrease in pressure and Increase in temperature causes the equation to move towards the reactants of the reaction

Learn more about equilibrium reaction : https://brainly.com/question/16878977

what’s the answer please

Answers

Answer:

5 × 10⁻³ mol

Explanation:

Step 1: Given data

Volume of HCl solution (V): 25 cm³Molar concetration of the HCl solution (C): 0.2 mol/dm³

Step 2: Convert "V" to dm³

We will use the conversion factor 1 dm³ = 1000 cm³.

25 cm³ × 1 dm³/1000 cm³ = 0.025 dm³

Step 3: Calculate the moles of HCl (n)

We will use the definition of molarity.

C = n/V

n = C × V

n = 0.2 mol/dm³ × 0.025 dm³ = 5 × 10⁻³ mol

Which statement best describes how an electromagnetic motor works?


Electrons are moved through a magnet, creating a current. That current interacts with a circuit, moving the

conductor in the orientation of the field


Electrons are moved through a current, creating a circuit That circuit interacts with a magnet, moving the

conductor in the orientation of the field.


Electrons are moved through a circuit, creating a current That current interacts with a magnet, moving the

conductor in the orientation of the field


Electrons are moved through a magnet, creating a circuit That circuit interacts with a current, moving the

conductor in the orientation of the field

Answers

Answer:

Electrons are moved through a magnet, creating a current. That current interacts with a circuit, moving the conductor in the orientation of the field.

Explanation:

Electro magnetic fields are used to create electric current by the movement of electrons. When a coil of wire is wrapped around a magnet it pushes electrons and they flow through a magnet to create current. This current interacts with circuit to move conductor.

2. What three states of matter do we see every day?
HELP PLEASEE FAST OMG

Answers

Answer: solids, liquids gases

Answer:

solid,liquids,gases & plasma

3. Which state of matter has a defined shape?
HELP FAST

Answers

Answer:

Solid state of matter has a definite shape

The answer to this is solids!

how does a buffer work?
A. it prevents added acids or bases from dissociating
B. it neutralizes acids or bases by precipitating a salt
C. it forms new conjugate pairs with the added ions
D. it bonds with the added H+ or OH- in solution​

Answers

Answer:

It bonds with the added H+ or OH in solution.

Explanation:

it initiates the healing process?​

Answers

Answer:

platelets?

Explanation:

the question is vauge. but I hope you got it right!

Answer:

Cell division ?

Explanation:

At a certain temperature this reaction follows first-order kinetics with a rate constant of 2.01 s^−1
CICH2CH2Cl (g) → CH2CHCI (g) + HCl(g)
Suppose a vessel contains CICH2CH2Cl at a concentration of 1.34 M. Calculate how long it takes for the concentration CICH2CH2Cl to decrease to 20.0% of its initial value. You may assume no other reaction is important. Round your answer to 2 significant digits.

Answers

Answer:

0.80 seconds (2 significant figures)

Explanation:

The equation of the reaction is given as;

CICH2CH2Cl (g) --> CH2CHCI (g) + HCl(g)

Rate constant (k) = 2.01 s^-1

From the units of the rate constant, this is a first order reaction.

Initial Concentration = 1.34 M

t = ?

Final concentration = 20% of 1.34 = 0.268 M

The integrated rate law for a first order reaction is given as;

ln[A] = ln[A]o - kt

ln(0.268) = ln(1.34) - 2.01(t)

-2.01(t) = - 1.6094

t = 0.8007 ≈ 0.80 seconds (2 significant figures)

How many molecules are there in 13.5g of lithium oxide?

please help! ​

Answers

Answer:

the answer is 29.8814

Explanation:

because this is the answer to your question

i looked it up and got 0.45178606089406353 as the exact number
i used an online converter

an ionic bond consist of a gas and metal

Answers

Answer: yes

Explanation:

What are the main sources of outdoor air pollution and how do they cause smog?​

Answers

Answer:

The common sources of outdoor air pollution are emissions caused by combustion processes from motor vehicles, solid fuel burning and industry. Other pollution sources include smoke from bushfires, windblown dust, and biogenic emissions from vegetation (pollen and mold spores).

smog is produced when sunlight reacts with nitrogen oxides in the atmosphere. Nitrogen oxides come from car exhaust, coal power plants, and factory emissions. When sunlight hits these chemicals, they form airborne particles and ground-level ozone—or smog.

1. How many molecules are in 4.5 moles?


Answers

Answer:

depends on what molecule you are looking for

Explanation:

In one mole of stuff (atoms, molecules, eggses), there are NA individual items of that stuff. So, there are 4.5 × NA BCl3 molecules; i.e. 4.5 × 6.022×1023 ≅ 27×1023 individual molecules of BCl3


HELP ASAP!!! Plzzz

How many total atoms of oxygen are present in the molecules represented here?

Answers

36 Oxygen atoms !!!!!!
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