Answer:
A. releases a large amount of heat
Explanation:
A reaction is said to be spontaneous if it can proceed on its own without the addition of external energy. A spontaneous reaction is not determined by the length of time, because some spontaneous reactions are completed after a long period of time. They are exothermic in nature. An example is the conversion of graphite to carbon which takes a long period of time to complete. Spontaneous reactions are known to increase entropy in a system. Entropy is the rate of disorder in a system.
In the combustion of fire, energy is released to the surroundings as there is a decrease in energy. This is an example of a spontaneous reaction because it is an exothermic reaction, which causes an increase in entropy and a decrease in energy.
Answer:it’s C
Explanation:
I just got it wrong and it showed the the right answer
Answer:
The mass of the jar and contents remained the same after the metal was burned.
Explanation:
My prediction about the experimental results is that the mass of the jar and contents remained the same after the metal was burned in the jar.
This is compliance with the law of conservation of mass which states that in a chemical reaction, matter is neither created nor destroyed by bonds are rearranged for new compounds to form.
- In compliance with this law, it is expected that the mass of the jar and its content will remain the same before and after the reaction.
- No new material was added and no material was removed from the jar.
Answer:

Explanation:
We are given a number of particles and asked to convert to moles.
<h3>1. Convert Particles to Moles </h3>
1 mole of any substance contains the same number of particles (atoms, molecules, formula units) : 6.022 *10²³ or Avogadro's Number. For this question, the particles are not specified.
So, we know that 1 mole of this substance contains 6.022 *10²³ particles. Let's set up a ratio.

We are converting 2.98*10²³ particles to moles, so we multiply the ratio by that value.

The units of particles cancel.



<h3>2. Round</h3>
The original measurement of particles (2.98*10²³) has 3 significant figures, so our answer must have the same.
For the number we found, 3 sig figs is the thousandth place.
The 8 in the ten-thousandth place (0.4948522086) tells us to round the 4 up to a 5 in the thousandth place.

2.98*10²³ particles are equal to approximately <u>0.495 moles.</u>