Answer:
alkaline earth metals
Group 2 metals, the alkaline earth metals, have 2 valence electrons, and thus form M2+ ions. The halogens, Group 17 , reach a full valence shell upon reduction, and thus form X− ions
Explanation:
Answer:corrosion (i believe)
Explanation:
Answer:
Please check the attached file for the diagram
Explanation:
The velocity of the of the rowboat
through the river is the resultant velocity. It is obtained taking a vector sum of the velocity in still water and the velocity of the river.
There are several ways to take this vector sum, but the question makes it simple for us to use Pythagoras's theorem because the East and North directions are perpendicular to each other.
Hence;


Answer:
The Balmer series refers to the spectral lines of hydrogen, associated to the emission of photons when an electron in the hydrogen atom jumps from a level
to the level
.
The wavelength associated to each spectral line of the Balmer series is given by:

where
is the Rydberg constant for hydrogen, and where
is the initial level of the electron that jumps to the level n = 2.
The first few spectral lines associated to this series are withing the visible part of the electromagnetic spectrum, and their wavelengths are:
656 nm (red, corresponding to the transition
)
486 nm (green,
)
434 nm (blue,
)
410 nm (violet,
)
All the following lines lie in the ultraviolet part of the spectrum. The limit of the Balmer series, corresponding to the transition
, is at 364.6 nm.
a) 1.48 m/s
The tuning fork is moving by simple harmonic motion: so, the maximum speed of the tip of the prong is related to the frequency and the amplitude by

where
is the maximum speed
is the angular frequency
A is the amplitude
For the tuning fork in the problem, we have
, where f is the frequency
is the amplitude
Therefore, the maximum speed is

b) 
The fly's maximum kinetic energy is given by

where
is the mass of the fly
is the maximum speed
Substituting into the equation, we find
