Answer:
Oxygen
Explanation:
because oxygen is used when making and sustaining a fire.
I think this seems like something is missing from the question
Transverse wave, motion in which all points on a wave oscillate along paths at right angles to the direction of the wave's advance. Surface ripples on water, seismic S (secondary) waves, and electromagnetic (e.g., radio and light) waves are examples of transverse waves.
Answer:
Atoms=9.033*10^23 atoms
Explanation:
Atoms=no.of miles*Avogadro's no.
Atoms=1.5*6.022*10^23
Atoms=9.033*10^23 atoms
Answer: One formula unit of NaCl consists of one cation, whose chemical symbol is
and one anion whose chemical symbol is 
Explanation:
For formation of a neutral ionic compound, the charges on cation and anion must be balanced. The cation is formed by loss of electrons by metals and anions are formed by gain of electrons by non metals.
The cation is formed by the metal sodium which forms
and the anion is formed by non metal chlorine which forms
.
For a formula unit of sodium chloride, the charges have to be balanced , thus the valencies of ions are exchanged and the neutral compound result. Thus
and
combine to form neutral 
Boiling Water is a physical change. When water gets to a certain temperature, it's boiling point starts.