Answer:
Temperature is a common type of controlled variable. If a temperature is held constant during an experiment, it is controlled. Other examples of controlled variables could be an amount of light, using the same type of glassware, constant humidity, or duration of an experiment.
Explanation:
8.50 moles is equal to 5.1187×10²⁴ atoms of Ca.
<u>Explanation:</u>
We have to multiply the moles of Ca by the Avogadro's number:
= 6.022×10²³
So the number of atoms:
= 8.5 moles × 6.022×10²³atoms / mol
= 5.1187×10²⁴ atoms
Hence the 8.50 moles is equal to 5.1187×10²⁴ atoms of Ca.
Balanced equation:
Mg + 2 HNO3 —> Mg(NO3)2 + H2
This is a metal + acid reaction giving salt and hydrogen (not water).
Uses of nonmetals in our daily life: Oxygen which is 21% by volume helps in the respiration process.
Nonmetals used in fertilizers: Fertilizers contain nitrogen.
Nonmetals used in crackers: Sulphur and phosphorus are used in fireworks.
Answer:The earths plates shifting
Explanation: The movement releases stored-up 'elastic strain' energy in the form of seismic waves, which propagate through the Earth and cause the ground surface to shake.