Sodium (Na) is a Alkali metal so that's the answer
Answer:
Magneta is a mix of blue and red and is a secondary colour.
Explanation:
As we can see green is the complementary colour of Magneta.Complementary colours are the pairs of colours which when combined cancel each other out. This means that when combined they produce a grayscale colour like white or black .
Light travels faster than sound ,because sound can only travel waves.
To solve this problem we need to apply the corresponding sound intensity measured from the logarithmic scale. Since in the range of intensities that the human ear can detect without pain there are large differences in the number of figures used on a linear scale, it is usual to use a logarithmic scale. The unit most used in the logarithmic scale is the decibel yes described as

Where,
I = Acoustic intensity in linear scale
= Hearing threshold
The value in decibels is 17dB, then

Using properties of logarithms we have,




Therefore the factor that the intensity of the sound was 
A water wave is an example of a mechanical wave. A wave that can travel only through matter is called a mechanical wave.