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2 years ago

Which reason best explains why metals are shiny?

Chemistry

1 answer:

ZanzabumX [31]2 years ago

5 0

Answer:

Best:

because their valence electrons absorb light

Minor:

because their valence electrons move to higher energy levels

Explanation:

When the electrons absorb light, they absorb this energy and they have a tedency to jump and get promoted to the high energy level.

As a result, they release out energy after being promoted. This energy is in form of light

$.$

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Based on the structure, which material will dissolve this biomolecule the best? dilute alcohol water oil ionic solution

alexdok [17]

I think that it would be ionic solution

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3 years ago

In humans, infections by fungi and protists are usually more difficult to treat than bacteria infections. Suggest an explanation

Basile [38]

<span>Fungal diseases are difficult to treat mainly because they are eukaryotic organisms just like us humans, and therefore have less differences for drugs to target without harming the human body as well. Most antibiotics target e.g. the peptidoglycan layer in the bacterial (a prokaryote) cell wall, which is a safe target since eukaryotic cells do not have equivalent structures. Similarly many differences in metabolic pathways between humans and prokaryotes is often targeted by antibiotics, but metabolism of fungi and humans is much more uniform, and hence it is difficult to exclusively target the fungi only.

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5 0

3 years ago

Read 2 more answers

Which substance has a mass is 13.5 grams, and its volume is 5 cm 3.

solmaris [256]

Answer:

Substance is Aluminium

Explanation:

We are given;

Mass; m = 13.5 grams

Volume; V = 5 cm³

Formula for density is;

density = m/V

Density = 13.5/5

Density = 2.7 g/cm³

From the table attached, we can see that the element with a corresponding density of 2.7 is Aluminium

5 0

3 years ago

A process at constant T and P can be described as spontaneous if ΔG < 0 and nonspontaneous if ΔG > 0. Over what range of t

creativ13 [48]

Answer:

Incomplete question, it is lacking the data it makes reference. The missing data from Chegg is:

2 SO3(g) → 2 SO2(g) + O2(g)

ΔHf° (kJ mol-1) -395.7 -296.8

S° (J K-1 mol-1) 256.8 248.2 205.1

ΔH° = kJ

S° = J K⁻¹

Explanation:

The method to solve this problem calls for the use of the Gibbs standard free energy change:

ΔG = ΔrxnH - TΔSrxn

We know a reaction is spontaneous when ΔG is < 0, so to answer this question we need to solve for the temperature, T, at which ΔG becomes negative.

Now as mentioned in the hint, we need to determine ΔrxnH and ΔSrxn, which are given by

ΔrxnH = ∑ ν x ΔfHº products - ∑ ν x ΔfHº reactants

where ν is the stoichiometric coefficient in the balanced chemical equation.

For ΔS we have likewise

ΔrxnS = ∑ ν x ΔSº products - ∑ ν x ΔSº reactants

Thus,

ΔrxnH(kJmol⁻¹) = 2 x (-296.8) - 2 x ( -395.7 ) = 197.8 kJ

ΔrxnS ( JK⁻¹) = 2 x 248.2 + 205.1 - 2 x 256.8 = 187.9 JK⁻¹ = 0.1879 kJK⁻¹

So ΔG kJ = 197.8 - T(0.1879)

and the reaction will become spontaneous when the term T(0.1879) becomes greater that 197.8,

0 = 197.8 - 0.1879 T ⇒ T = 1052 K

so the reaction is spontaneous at temperatures greater than 1052 K (780 ºC)

4 0

3 years ago

Earths mantle is made of a dense thick material that allows movement of crystal plates. Crust plate movement occurs because the

nasty-shy [4]

Answer:

Convection cells

7 0

2 years ago