Answer:
Na(OH)²
Explanation:
We look for the charges in the periodic table
Answer:

Explanation:
Alkaline earth metals are in group 2. The number of valence electrons of elements in group 2 is 2.
Answer: (C)
The frequency increases as the wavelength decreases
Explanation:
The relation between the frequency and wavelength of a wave is
Frequency = 1 / Wavelength
The Frequency of electromagnetic wave is inversely proportional to the wavelength. So, as the frequency increases, the wavelength of the wave decreases and vise-versa.
The frequency of a wave is number of complete cycles passing a particular point per second. Its S.I unit is Hertz whereas the wavelength of a wave is the distance between two consecutive crest and trough in meters.
So, on increasing the frequency of a wave, there will be more number of the cycles of wave per second which will decrease the distance between the consecutive crest and trough i.e wavelength.
Answer:
Answer: B. Water condenses to form clouds.
Explanation:
When the moisture condenses, this results in the release of energy. The energy causes the air to be warm and results in the rise of air in the upper atmosphere. This process results in the instability in the atmosphere and cumulonimbus clouds are formed. These clouds support lightening during a thunderstorm.