GS One‑Liners
high‑yield facts · smart revision
5107
facts
5107
results
Latest facts first
| # | Question & Answer |
|---|---|
| 4001 |
What happens to bases in water?
-
They dissociate to form hydroxide ions (OH⁻)
|
| 4002 |
What happens to acids in water?
-
They ionize to form hydrogen ions (H⁺)
|
| 4003 |
What is a Bronsted-Lowry base?
-
A proton (H⁺) acceptor
|
| 4004 |
What is a Bronsted-Lowry acid?
-
A proton (H⁺) donor
|
| 4005 |
What is an Arrhenius base?
-
A substance that releases OH⁻ ions in aqueous solution
|
| 4006 |
What is an Arrhenius acid?
-
A substance that releases H⁺ ions in aqueous solution
|
| 4007 |
What are the practical applications of noble gases?
-
Lighting (Ne), helium balloons (He), inert atmosphere for welding (Ar)
|
| 4008 |
What is the significance of hydrogen in the periodic table?
-
Placed in Group 1 or 17; versatile in forming compounds
|
| 4009 |
What is the relationship between ionization energy and reactivity of metals?
-
Lower ionization energy → higher metallic reactivity
|
| 4010 |
How does reactivity of non-metals vary?
-
Decreases down a group, increases across a period
|
| 4011 |
How does reactivity of metals vary?
-
Increases down a group, decreases across a period
|
| 4012 |
How does metallic character vary down a group?
-
Increases down the group
|
| 4013 |
How does metallic character vary across a period?
-
Decreases from left to right
|
| 4014 |
What is the significance of periodic trends?
-
Predict chemical reactivity, bond formation, and physical properties of elements
|
| 4015 |
Which element has the largest atomic size in a period?
-
Group 1 elements (e.g., Lithium in first period)
|
| 4016 |
Which element has the highest electronegativity?
-
Fluorine (F)
|
| 4017 |
How does modern periodic table solve the limitations of Mendeleev’s table?
-
Arranges elements by atomic number, corrects anomalies in order of properties
|
| 4018 |
What is the half-life of a radioactive substance?
-
Time taken for half the nuclei of a radioactive substance to decay
|
| 4019 |
What are the types of radioactive emissions?
-
Alpha (α), Beta (β), and Gamma (γ) rays
|
| 4020 |
Who discovered radioactivity?
-
Henri Becquerel
|
| 4021 |
What is radioactivity?
-
Spontaneous emission of particles or radiation from unstable atomic nuclei
|
| 4022 |
Give examples of noble gases.
-
Helium (He), Neon (Ne), Argon (Ar)
|
| 4023 |
What are noble gases?
-
Group 18 elements with complete valence shells, chemically inert
|
| 4024 |
What is unique about hydrogen?
-
Can behave like an alkali metal (H⁺) or halogen (H⁻), forms covalent bonds, smallest atom
|
| 4025 |
How does electronegativity vary down a group?
-
Decreases down the group
|