Physical change
iron nail have high melting point, thus, when it is heated, it will not melt very easily.
chemical change
iron nail can rust due to the exposure to the air(oxygen). iron in the nail and oxygen in the air will react together to form iron oxide(rust).
furthermore, the reaction is irreversible.
Answer:
A. Gas atoms subjected to electricity emit bright lines of light
Explanation:
When subjected to electricity, the electrons of a gas atom are <em>excited</em>. From that excited energy level, the electrons eventually go back to their initial state; this <u>transition</u> is done by emitting photons at a specific wavelength (causing an emission of bright lines of light).
Such is the mechanism of gas-discharge lamps tipically found in households.
Answer:
The volume would be; 136.17 ml
Explanation:
Volume V1 = 150 mL
Temperature T1 = 20°C + 273 = 293 K
Pressure P1 = 758 - 17.54 = 740.46 torr
At STP;
Volume V2 = ?
Pressure P2 = 760 torr
Temperature T2 = 273 K
Using the general gas equation;
P1V1 / T1 = P2V2 / T2
Making V2 subject of formulae;
V2 = P1V1T2 / T1P2
Inserting the values we have;
V2 = 740.46 * 150 * 273 / 293 * 760
V2 = 136.17 ml
balance the chemical reaction by the oxidation reduction method Phosphorus + Sodium Hydroxide + water
Answer:
Silver and copper
Explanation:
Siliver
Electrical conductivity=62000000(s/m)
Boiling point=2162
Melting point=961.78
Phase=solid
Copper
Electrical conductivity=59000000(s/m)
Boiling point =2927
Melting point=1084.62
Phase=soild
Metals like gold, silver and copper are drawn into thin wire and are used in an electric circuit because of their high electrical conductivity
Mostly Siliver and copper are used since using gold is much expensive.
