The pic is the question! Please help

Answer:

2 [tex]\pi[/tex] r

Explanation:

Given that:

Radius of basketball  = 9inches

Unknown:

Hoop's circumference  = ?

Solution:

To solve this problem, we use the formula for the circumference of a circle.

The shape of the hoops is circular.

 Circumference of a circle = 2 [tex]\pi[/tex] r

R is the radius of the basketball hoop

Answer:

D. 2NO2(g) → N204(9)

Explanation:

A p e x

2NO[tex]_2[/tex](g) → N[tex]_2[/tex]O[tex]_4[/tex](g) reactions would have a decrease in entropy. Therefore, the correct option is option D.

Entropy is a measureable physical characteristic and a scientific notion that is frequently connected to a condition of disorder, unpredictability, or uncertainty. From classical thermodynamic, where it was originally recognized, towards the microscopic explanation of nature within statistical physics, the name and concept are employed in a variety of disciplines.

It has numerous applications in physics and chemistry, biological systems and how they relate to life, cosmology, economics, society, weather science, and information systems, especially the exchange of information. 2NO[tex]_2[/tex](g) → N[tex]_2[/tex]O[tex]_4[/tex](g) reactions would have a decrease in entropy.

Therefore, the correct option is option D.

To know more about entropy, here:

https://brainly.com/question/14131507

#SPJ7

Answer:

Diaphragm controls the amount of light reaching the specimen. It is located above the condenser and below the stage. Most high quality microscopes include an Abbe condenser with an iris diaphragm. Combined, they control both the focus and quantity of light applied to the specimen.

Answer:

distance divided by time so A

Explanation:

Answer:

12

Explanation:

Answer:

(c) only solute present

Explanation:

In chemistry, the mole fraction, denoted by X, refers to the number of moles of a substance in a compound/mixture divided by the total number of substances in the same compound or mixture.

In this case, we can say that mole fraction represents the number of solutes to the number of solutes and solvent in the solution i.e. X = nA/nA + nB

Where; nA = number of solutes

nB = number of solvent

X = mole fraction.

Based on this analogy, When the mole fraction of solute is 1, there is only solute present. That is; X = 1 / 1 + 0

X = 1/1 = 1.

Answer:

Lithium

Explanation:

Answer:

all of the above

Explanation:

all of this is in the solar system

Answer:

E

Explanation:

Look at bottom numbers.

90 → 88 + x

it means,

90=88+x

hence x = 2

it is also valid for top numbers.

230=226+y

y = 4

Answer:The electron has a negative charge and the proton has a positive charge, and these charges work against each other to make the electromagnetic force that holds the entire atom together.

Explanation:

This is the answer

Answer:

9.64g/mL

Explanation:

Given parameters:

Mass of the metal  = 106g

Volume of cylinder = 50mL

Volume difference  = 31mL  - 20mL  = 11mL

Unknown:

Density of the metal  = ?

Solution:

To find the density of the metal, we use;

 Density  = [tex]\frac{mass}{volume}[/tex]  

 Density  = [tex]\frac{106}{11}[/tex]   = 9.64g/mL

Answer:

20%

Explanation:

10.0 = 100%

8.00 = 80%

100-80= 20

Answer:

it is called the prevailing westerlies

Explanation:

Answer: a) [tex]78.2m^2[/tex]

b) [tex]1.2\times 10m^2[/tex]

c) [tex]2.5m^2[/tex]

d) [tex]81.1m^2[/tex]

Explanation:

Significant figures : The figures in a number which express the value -the magnitude of a quantity to a specific degree of accuracy is known as significant digits.

Rules for significant figures:

1. Digits from 1 to 9 are always significant and have infinite number of significant figures.

2. All non-zero numbers are always significant.  

3. All zero’s between integers are always significant.

4. All zero’s preceding the first integers are never significant.

5. All zero’s after the decimal point are always significant.

The rule apply for the multiplication is :

The least number of significant figures in any number of the problem determines the number of significant figures in the answer.

a) [tex]24m\times 3.26m=78.2m^2[/tex]    

b) [tex]120m\times 0.10m=1.2\times 10m^2[/tex]

c) [tex]1.23m\times 2.0m=2.5m^2[/tex]

d) [tex]53.0m\times 1.53m=81.1m^2[/tex]

Answer:

There are 1.4754246675000002e+24 atoms of Hydrogen within the measurement of 2.45 moles of hydrogen!

Explanation:

Answer:

28 %

Explanation:

Mass mass N2O = 28 + 16 = 44 mass nitrogen = 2 x 14 = 28 % nitrogen Chemistry.

Answer is : It is a good thermal and electrical conductor. -The main point to be noted is that aluminium is a highly reactive element and still it is used for making cooking utensils. The reason is that aluminium has a very high affinity for oxygen. So, it reacts with oxygen and forms a layer of aluminium oxide on its surface.

Answer:

This is because aluminium reacts with oxygen present in air to form a thin layer of aluminium oxide . This oxide layer is very stable and prevents further reaction of aluminium with oxygen . Also , it is light in weight and a good conductor of heat Hence , it is used to make cooking utensils .

Explanation:

Believe it

Answer:

d. Electrons have a negative charge and are lighter than protons

Explanation:

The best statement that describes electrons is that electrons are negatively charged and are lighter than protons.

There are three known subatomic particles which are:

The mass of the protons and neutrons are similar.

Electrons are lighter than both protons and neutrons.

Answer:

1.  

First of all, let's convert the energy of the absorbed photon into Joules:

The energy of the photon can be rewritten as:

where

h is the Planck constant

c is the speed of light

is the wavelength of the photon

Re-arranging the formula, we can solve to find the wavelength of the absorbed photon:

2. 1.24 eV

In this case, when the electron jumps from the n=4 level to the n=3 level, emits a photon with wavelength

So the energy of the emitted photon is given by the formula used previously:

and using

we find

converting into electronvolts,

Explanation:

There are 1.93 x 10²⁴ particles

Given

3.2 moles of Neon gas

Required

Number of particles

Solution

The mole is the number of particles(molecules, atoms, ions) contained in a substance  

1 mol = 6.02.10²³ particles

Can be formulated

N=n x No

N = number of particles

n = mol

No = Avogadro's = 6.02.10²³

So the number of particles for 3.2 moles :

N = 3.2 x 6.02.10²³

N = 1.93 x 10²⁴

or

we can describe it using Avogadro's number conversion factor

[tex]\tt 3.2~moles\times \dfrac{6.02\times 10^{23}}{1~mole}=1.93\times 10^{24}[/tex]

Answer:

Explanation:

I can help

Answer:

12.67g of Mg / 15.33g of MgO * 100% = 82.6% of Mg

Explanation:

Answer:

I believe the answer is A. molecules are larger than atoms so they should be visible and atoms and molecules are indeed different

To see the number of atoms of an element in a given molecule we need to multiply stoichiometry to the number that is written on the foot of the element that is stoichiometry. Therefore, the correct option is option A.

Atom is the smallest particle of any element, molecule or compound. Atom can not be further divided. Atoms contains nucleus in its center and electron that revolve around the atom in fixed orbit.

In the nucleus, proton and neutron are present. Electron has -1 charge while proton has +1 charge. Neutron is neutral that is it has no charge. So overall the charge of nucleus is due to only proton, not by neutron.  Most atoms are bonded together to make a molecule. Molecules combine to form compounds.

Therefore, the correct option is option A.

To know more about atom, here:

https://brainly.com/question/13518322

#SPJ2

Answer:

O Chlorine is more reactive than bromine.

Explanation:

From this experiment we can conclude that chlorine is more reactive than bromine and it is the reason why the reaction is able to proceed.

Answer:

b. 0.50 moles

Explanation:

To solve this problem we use Avogadro's number (6.023x10²³ atoms/mol).

By dividing the number of atoms (or molecules) by that number, we can calculate how many moles they represent.

So the answer is option b. 0.50 moles.

Answer:

dry cell

Explanation:

because it stops when salt distribution becomes equal as bridge is not added

Answer:

a

Explanation:

a p e x :)

Answer:

pretty sure it's false

Explanation:

hope this helps!

Answer:

True

Explanation:

An element is pure substance that conatin only one type of atom

Answer:

true

Explanation:

the element hydrogen is made from atom

Answer:

The amount of CaCO₃ Jeeves needs to find is approximately 71.392 grams

Explanation:

The given parameters are;

The mass of the CaO required = 40 g

The chemical reaction for the production of CaO from CaCO₃ is given as follows;

CaCO₃(s) → CaO(s) + CO₂(g)

Therefore, 1 mole of CaCO₃ produces 1 mole of CaO and 1 mole of CO₂,

The molar mass of CaO = 56.0774 g/mol

Number of moles, n = Mass/(Molar mass)

The number of moles of CaO = 40 g/(56.0774 g/mol) ≈ 0.7133 moles of CaO

Therefore, given that 1 mole of CaO is produced from 1 mole of CaCO₃ 0.7133 moles of CaO will be produced from 0.7133 moles of CaCO₃

The molar mass of CaCO₃ = 100.0869 g/mol

Mass = The number of moles × The molar mass

∴ The mass of CaCO₃ Jeeves needs to find = 0.7133 moles × 100.0869 g/mol ≈ 71.392 g

The mass of CaCO₃ Jeeves needs to find ≈ 71.392 grams.

Answer:

B. Geostationary Operational Environmental Satellite

Explanation:

Hope this helps!

Answer:

B

Explanation:

I’m studying it for you!

Answer:

B. Isotopes mean having differing number of neutrons but having the same amount of protons basically.

Explanation:

B. The atoms are isotopes of each other

Given

The first atom : 8 protons, 8 neutrons and 8 electrons

The second atom : 8 protons, 10 neutrons and 10 electrons

Required

Comparison

Solution

A. Atom is said to be neutral if the number of protons and electrons is the same

The first atom neutral

The second atom - anion : charge = -2(10 electron-8 proton)

B. isotopes = the same atomic number and different mass number

The first atom : atomic number = 8, mass number = 16

The second atom neutral : atomic number = 8, mass number = 18

Both : isotopes

C. First atom = neutral, second atom anion (charge = -2)

D. Can exist in nature