Answer: Smoking cigarettes
Explanation: The other options don't cause pollution to form in the air besides smoking, from the particles it creates causing harm and damage to your lungs and fill the air with smoke particles.
C, electrons. Ion<span> of an </span>element has<span> the </span>same<span> nucleus, the </span>same number<span> of protons and neutrons, with a </span>different number<span> of electrons.</span>
Answer:

Explanation:
Speed of light is the product of its wavelength and frequency, expressed as
S=fw
Where s represent speed, f is frequency while w is wavelength
Making f the subject of the formula then
f=s/w
Substituting 2.99x10^8 m/s for s and 3.012x10^-12 m for w then

Therefore, the frequency equals to 
The temperature rises until the water reaches the next change of state — boiling. As the particles move faster and faster, they begin to break the attractive forces between each otherand move freely as steam — a gas. The process by which a substance moves from the liquid state to the gaseousstate is called boiling.
Answer:
can you explain more or..,.
Explanation: