User M.A.R.

222

votes

3

answers

30k

views

Why is gold golden?

Jun 5 at 14:45 Mathew Mahindaratne 26.2k

211

votes

1

answer

60k

views

Why can we smell copper?

everyday-chemistry metal transition-metals smell

Apr 17 '18 at 9:42 Archer 4,560

170

votes

8

answers

147k

views

Can an atom have more than 8 valence electrons? If not, why is 8 the limit?

physical-chemistry electrons electronic-configuration valence-bond-theory

Dec 15 '17 at 20:44 Oscar Lanzi 27k

108

votes

8

answers

63k

views

Is a negative pH level physically possible?

acid-base equilibrium ph

Aug 10 '19 at 8:56 Community♦ 1

96

votes

5

answers

77k

views

How do you melt metals with super high melting points?

melting-point

Mar 15 '17 at 6:35 KyleCPM 1

83

votes

7

answers

121k

views

Why is the 2s orbital lower in energy than the 2p orbital when the electrons in 2s are usually farther from the nucleus?

energy electrons quantum-chemistry orbitals

Dec 24 '19 at 6:20 Community♦ 1

81

votes

2

answers

31k

views

What is Bent's rule?

bond orbitals hybridization stereochemistry valence-bond-theory

Oct 21 '16 at 22:54 Community♦ 1

74

votes

4

answers

35k

views

Bonding in diatomic C2, a carbon-carbon quadruple bond?

theoretical-chemistry bond molecular-orbital-theory covalent-compounds

Jun 13 at 14:57 Mathew Mahindaratne 26.2k

64

votes

4

answers

30k

views

Why do elements in columns 6 and 11 assume 'abnormal' electron configurations?

orbitals electronic-configuration transition-metals

Dec 24 '19 at 6:28 Community♦ 1

64

votes

4

answers

19k

views

How does Walter White make pure crystal meth using a non-stereospecific reaction?

reaction-mechanism stereochemistry chemistry-in-fiction

Aug 15 '19 at 19:14 orthocresol♦ 56k

60

votes

4

answers

49k

views

How can one explain niobium’s weird electronic configuration?

electronic-configuration transition-metals

Aug 22 '19 at 15:31 shibu sarkar 1

57

votes

4

answers

213k

views

Why add water first then acid?

acid-base experimental-chemistry safety

May 17 '19 at 6:42 Melanie♦ 6,184

54

votes

3

answers

9k

views

Why do we write NH3?

inorganic-chemistry nomenclature

Feb 11 '16 at 17:47 Community♦ 1

52

votes

2

answers

53k

views

What makes some metals melt at higher temperature?

melting-point metal

Dec 24 '19 at 7:10 Mathew Mahindaratne 26.2k

52

votes

5

answers

10k

views

The last element's atomic number

physical-chemistry atoms nuclear elements

Jan 21 '18 at 17:44 Tyberius 10k

49

votes

1

answer

10k

views

Why does menthol (e.g. peppermint) feel cool to the tongue?

biochemistry

Oct 19 '15 at 14:04 Community♦ 1

45

votes

5

answers

69k

views

Why does bond angle decrease in the order H2O, H2S, H2Se?

bond periodic-trends hybridization molecular-structure

Jan 21 '19 at 23:29 Andrew 5,855

44

votes

4

answers

46k

views

Why do the names of most chemical elements end with -um or -ium?

nomenclature elements

Mar 21 '17 at 14:52 Community♦ 1

42

votes

5

answers

7k

views

How can antibonding orbitals be more antibonding than bonding orbitals are bonding?

bond quantum-chemistry molecular-orbital-theory

Dec 27 '18 at 12:46 Tan Yong Boon 8,494

41

votes

1

answer

5k

views

Why is methane's molecular formula conventionally “CH₄”, while water is “H₂O” (among others)?

nomenclature notation

Feb 21 '15 at 22:27 ron 78.1k

41

votes

3

answers

8k

views

Carbon atoms at the edge of a diamond

crystal-structure hybridization

Apr 22 '19 at 14:43 Jaimes Beam 1

41

votes

5

answers

41k

views

Is there any substance that's a 4-4-4 on the NFPA diamond?

safety toxicity

Oct 17 '17 at 3:09 andselisk♦ 31.7k

41

votes

4

answers

7k

views

What is more acidic: D3O+ in D2O or H3O+ in H2O and why?

acid-base kinetics isotope

Jun 19 '19 at 22:28 Mathew Mahindaratne 26.2k

40

votes

4

answers

44k

views

The reason behind the steep rise in pH in the acid base titration curve

acid-base ph

Oct 25 at 7:08 G M 8,579

40

votes

3

answers

5k

views

Do molecules with bridges through rings exist?

organic-chemistry molecular-structure molecules

Jun 30 at 11:23 Mathew Mahindaratne 26.2k

40

votes

1

answer

87k

views

Differences between phenols and alcohols

organic-chemistry alcohols phenols

Nov 5 '19 at 23:00 Community♦ 1

40

votes

3

answers

13k

views

Why do impurities lower the melting point of an isolated substance?

thermodynamics mixtures melting-point

Dec 14 '15 at 12:19 M.A.R. 9,660

39

votes

3

answers

107k

views

What is the inert pair effect?

inorganic-chemistry quantum-chemistry orbitals periodic-trends relativistic

Mar 1 '18 at 18:48 pentavalentcarbon 7,091

38

votes

2

answers

7k

views

Why is arsenous acid denoted H3AsO3?

inorganic-chemistry acid-base nomenclature

Mar 19 '19 at 4:32 A.K. 11.4k

38

votes

4

answers

8k

views

What exactly is happening when sodium, potassium, or other alkali metal explodes in water?

physical-chemistry reaction-mechanism explosives

Jul 7 at 16:57 Mathew Mahindaratne 26.2k

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Why is gold golden?

Why can we smell copper?

Can an atom have more than 8 valence electrons? If not, why is 8 the limit?

Is a negative pH level physically possible?

How do you melt metals with super high melting points?

Why is the 2s orbital lower in energy than the 2p orbital when the electrons in 2s are usually farther from the nucleus?

What is Bent's rule?

Bonding in diatomic C2, a carbon-carbon quadruple bond?

Why do elements in columns 6 and 11 assume 'abnormal' electron configurations?

How does Walter White make pure crystal meth using a non-stereospecific reaction?

How can one explain niobium’s weird electronic configuration?

Why add water first then acid?

Why do we write NH3?

What makes some metals melt at higher temperature?

The last element's atomic number

Why does menthol (e.g. peppermint) feel cool to the tongue?

Why does bond angle decrease in the order H2O, H2S, H2Se?

Why do the names of most chemical elements end with -um or -ium?

How can antibonding orbitals be more antibonding than bonding orbitals are bonding?

Why is methane's molecular formula conventionally “CH₄”, while water is “H₂O” (among others)?

Carbon atoms at the edge of a diamond

Is there any substance that's a 4-4-4 on the NFPA diamond?

What is more acidic: D3O+ in D2O or H3O+ in H2O and why?

The reason behind the steep rise in pH in the acid base titration curve

Do molecules with bridges through rings exist?

Differences between phenols and alcohols

Why do impurities lower the melting point of an isolated substance?

What is the inert pair effect?

Why is arsenous acid denoted H3AsO3?

What exactly is happening when sodium, potassium, or other alkali metal explodes in water?