i dont know the answer pls help me​

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:

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:

Explanation:

I can help

Answer:

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

Explanation:

Answer:

Lithium

Explanation:

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:

B. Geostationary Operational Environmental Satellite

Explanation:

Hope this helps!

Answer:

B

Explanation:

I’m studying it for you!

Explanation:

1)

2Fe+3Cl2 →2FeCl3

2)

CH4+2O2 → CO2 +2H2O

3)

SnO2+2H2 →2H2O +Sn

4)

2KOH + H2SO4 → K2SO4+2H2O

Answer:

Mass = 15.12 g

Explanation:

Given data:

Mass of sodium borohydride = ?

Number of moles of sodium borohydride =0.40 mol

Solution:

Formula:

Mass = number of moles / molar mass

Molar mass of sodium borohydride = 37.8 g/mol

By putting values,

Mass = 0.40 mol × 37.8 g/mol

Mass = 15.12 g

Answer:

it is called the prevailing westerlies

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]

320 g IF₇

Math

Pre-Algebra

Order of Operations: BPEMDAS

Chemistry

Atomic Structure

Step 1: Define

7.3 × 10²³ molecules IF₇

Step 2: Identify Conversions

Avogadro's Number

Molar Mass of I - 126.90 g/mol

Molar Mass of F - 19.00 g/mol

Molar Mass of IF₇ - 126.90 + 7(19.00) = 259.9 g/mol

Step 3: Convert

Step 4: Check

Follow sig fig rules and round. We are given 2 sig figs.

315.056 g IF₇ ≈ 320 g IF₇

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

Answer: in the daytime the sun is out so the stars are not visible becuase the suns reflection! At night When you gaze at the constellations, every star produces an image that's the same size, but your retina isn't sensitive enough to respond to the outer parts of those images except for the brighter stars — which therefore look bigger than the fainter ones.

Explanation:

This is what I found on goog.le a while ago now it might actually help if I’m wrong I apologiz, I hope this was your quistion!

Answer:

This compound is HNO2

Explanation:

HNO2 ----> H+ + NO2

When metals and non metals combine in fixed proportion then a chemical compound is formed So, the compound that will be formed from  hydrogen ion and nitrate ion is Hydrogen nitrate.

Chemical formula is a formula where cation and anion combine to form a molecule in fixed proportion. Metals combine in form of cation and non metals combine in form of anion.

Cation is the species that give electron and attain positive charge while anion is a species which gain electron and attains negative charge so when anion and cation combine in fixed ration the the overall charge of the molecule is zero that is molecule is neutral, the charge over cation and anion is also called oxidation state.

Therefore, the compound that will be formed from hydrogen ion and nitrate ion is Hydrogen nitrate.

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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:

28 %

Explanation:

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

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:

(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:

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 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:

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:

Household cleaners, antiseptics and battery juice are examples of toxic chemicals that you cannot consume because they have high acids concentrations. However some are very healthy such as critic acids found in oranges. :) Hope this helped.

Explanation:

There is a limit to different things we encounter around the universe due to a lot of reasons.

To overcome these barriers, some catalysts that are not readily available are needed. This reduces the combination of some atoms in nature.

This and many more reasons limits the combination of chemical substances.

There is a limit to different things we encounter around the universe due to a lot of reasons:

So, for a chemical reaction to occur there are certain parameters that need to taken into consideration for a chemical reaction to actually takes place.

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Answer:

11508 liters

Explanation:

The Faruq family uses 548 liters of water per day.  The Chammas family uses 3 times as much water  per day. How much water does the Chammas family use per week?

Solution:

The amount of water used by the Chammas family is three times that of the Faruq family per day, hence:

Amount of water used by Chammas family in a day = 3 * water used by Faruq family in a day

Amount of water used by Chammas family in a day = 3 * 548 = 1644 liters

The amount of water used by the Chammas family in a week = 1644 liters per day * 7 days in a week = 11508 liters

Therefore 11508 liters of water was used by the Chammas family in a week

Answer:

distance divided by time so A

Explanation:

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:

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.

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Answer:

all of the above

Explanation:

all of this is in the solar system

Answer:

The unit for mass is the kilogram (Kg).

Explanation:

Hope this helped!! <3 good luckk!!

Answer:

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

Explanation: