Answer:
The cathode reaction is NiO2+H2O+2e−→Ni(OH)2+2OH−.
Answer : The correct option is, (D) CO₂, BCl₃, and Fe³⁺
Explanation :
According to the Lewis concept, an acid is defined as a substance that accepts electron pairs and base is defined as a substance which donates electron pairs.
(a) 
It is a Lewis-acid because it can accepts electron pairs.
(b) 
It is not a Lewis-acid because it can not accepts electron pairs but it is a base because it can donates and accept hydrogen ion.
(c) 
It is a Lewis-acid because it can accepts electron pairs because it has an incomplete octet and an empty 2p orbital.
(d) 
It is a Lewis-acid because it can accepts electron pairs.
Hence, the ions which behave as Lewis acids are, CO₂, BCl₃, and Fe³⁺
Answer is: Rutherford demonstrate that J.J Thompson's Plum Pudding model was not accurate.
Rutherford theorized that atoms have their charge concentrated in a very small nucleus.
This was famous Rutherford's Gold Foil Experiment: he bombarded thin foil of gold with positive alpha particles (helium atom particles, consist of two protons and two neutrons).
Rutherford observed the deflection of alpha particles on the photographic film and notice that most of alpha particles passed straight through foil.
That is different from Plum Pudding model, because it shows that most of the atom is empty space.
Ionic bond is formed by two opposite type of substances (metal and non-metal) while both covalent or metallic bond is formed by two same type of substances (non-metal and non-metal form covalent bond, metal and metal form metallic bond). Idk if it's true or not.
Answer:
(a) W
(b) X
(c) Y
Explanation:
Let's consider the following table with melting and boiling points for 4 substances.
Substance Melting Point (°C) Boiling Point (°C)
W -7 60
X 660 2500
Y 180 1330
Z 115 445
Let's consider that:
- Below the melting point, a substance is solid.
- Between the melting and the boiling point, a substance is liquid.
- Above the boiling point, a substance is gas.
(a) Which substance is a gas at 100°C?
At 100 °C, W is above the boiling point
(b) Which substance is a liquid for the largest range of temperature?
The largest difference between the melting point and the boiling point is that of X: 2500 - 660 = 1840.
(c) Which substance is liquid at 1000 °C and a gas at 2000°C?
Y is between the melting and the boiling point at 1000 °C and above the boiling point at 2000 °C.
