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3 years ago

PLS HELP ME

Chemistry

1 answer:

DIA [1.3K]3 years ago

4 0

Number of men required to stand on top of each other to reach moon from earth are :

$\boxed{ \boxed{ \: \: \: \: \: \: \: 210320000 \: \: \: \: \: \: \: }}$

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How does the crystalline structure of a metal differ from the structure of an ionic compound, such as sodium chloride or cesium

Sergio [31]

Answer:

The metal cube lattice is made of only one kind of atom.

Explanation:

As we know that metallic crystals are made up of only one kind of element. A metal crystal is actually a huge sea of positive charges embedded in the layers of negative charges (electrons). The whole crystal is made up of same kind of atoms, e.g crystals of gold, crystals of iron.

If we talk about structure of metallic crystal, it can be body centered cubic, simple cubic, hexagonal or close cubic packing.

Now, coming towards the ionic crystals, we know that they are basically the crystals of ionic compounds like sodium chloride or cesium chloride. These crystals are formed due to ionic bonding between two or more than two kinds of elements/atoms. It is not possible for an ionic crystal to be composed of only one kind of atom. As far as structure is concerned, they can have different structure based on bonding between atoms in an ionic compound, e.g NaCl has octahedral geometry.

Therefore, it is very evident that best option is A.

7 0

3 years ago

Valence electrons determine...(one word)

zepelin [54]

Valence electrons determine its valency ? (The group, as in its oxidation state and stability)

6 0

3 years ago

If the temperature of a gas confined to such a cylinder is raised from 287°C to 587°C, what is the ratio of the initial volume t

jenyasd209 [6]

Answer:

1 : 2

Explanation:

From the question given, we obtained the following information:

T1 = 287°C = 287 +273 = 560K

T1 = 587°C = 587 +273 =860K

V1 = V

V2 =?

V1 /T1 = V2 /T2

V/560 = V2/860

Cross multiply

V2 x 560 = 860 x V

Divide both side by 560

V2 = (860 x V) / 560

V2 = 1.54V = 2V

The ratio of initial to final volume =

V1 : V2

= V : 2V

= 1 : 2

8 0

3 years ago

From the mass of Al reacted, how many moles are present? What is the mole ratio between Al and H2 in the balanced chemical react

tigry1 [53]

Answer:

From the mass of Al reacted, how many moles are present? We don't have the mass of Al reacted

What is the mole ratio between Al and H2 in the balanced chemical reaction?

By stoichiometry, ratio between Al and H₂ is 3:2

What units are required on the temperature when doing calculations with gases? °K degrees

The value of R is 0.082 L.atm/mol.K

Explanation:

A chemical reaction for this can be this one:

2Al (s) + 6HCl (aq) → 2AlCl₃(aq) + 3H₂ (g)

Balanced

To get the moles which are present in the mass of Al reacted you must calculate:

Al Mass / Al molar mass = Al moles

The Ideal Gas equation is this one:

Pressure . Volume = n° moles . R (gases constant) . T°K

The temperature must be in K, because the units of R

We usually use R = 0.082 L.atm/mol.K

5 0

3 years ago

A certain material has a normal freezing point of 10ºC and a normal boiling point of 70ºC. What state is the material in at room

ahrayia [7]

Explanation:

A freezing point is defined as the point in which a liquid state of a substance changes into solid state.

Whereas boiling point is defined as the point at which liquid state of substance starts to convert into vapor state.

So, a substance is freezing at $10^{o}C$ and boils at $70^{o}C$ then it means at room temperature, that is, around $25^{o}C$ the substance is present in liquid state.

This is because between the freezing and boiling point a substance will always exist in liquid state.

Thus, we can conclude that state of the material at room temperature is liquid.

5 0

3 years ago