Answer:
A. They must be kept separate from moisture and oxygen
Explanation:
Alkali metals refers to a group of chemical elements in the periodic table. It is the common name given to Group 1 elements (excluding hydrogen). They are generally metallic in nature with physical properties like shining lustre, silvery in appearance etc. Alkali metals include lithium, Pottasium, Sodium, Rubidium etc.
One important chemical property of alkali metals is their high reactivity i.e. they tend to react quickly with other substances. For example, alkali metals react vigorously with water to form hydroxides. They also react with oxygen to form oxides. Due to this highly reactive properties, they are kept or stored away from moisture (water) and oxygen (present in air).
Answer:
1 a person sings into a microphone
2 the sound is converted into an electrical signal
3 the analog signal is converted into a digital signal made of many samples of the digital sound
4 the samples of the sound is converted into 1s and 0s
5 the digital pattern is converted to a medium such as a hard disk or flash drive
Explanation: