Answer:
The number of protons and electrons are equal.
Explanation:
When an atom has an equal number of electrons and protons, it has an equal number of negative electric charges (the electrons) and positive electric charges (the protons). The total electric charge of the atom is therefore zero and the atom is said to be neutral.
<u>Answer:</u> The amount of energy required to raise the given amount of temperature is 6400 J
<u>Explanation:</u>
To calculate the heat absorbed by the lead, we use the equation:

where,
q = heat absorbed
m = mass of lead = 200 g
c = heat capacity of lead = 0.128 J/g°C
= change in temperature = 250°C
Putting values in above equation, we get:

Hence, the amount of energy required to raise the given amount of temperature is 6400 J
Answer: The mole ratio of Zn to ZnO is 3: 3.
Explanation:
According to law of conservation of mass, mass can be neither be created nor be destroyed. The mass on reactant side must be equal to the mass on product side. Thus the atoms of each element on both side of the reaction must be same.
The balanced chemical reaction is:

Here 3 moles of Zn combine with 2 moles of
to give 1 mole of
and 3 moles of
. Thus the mole ratio of Zn to ZnO is 3: 3.
Answer:
The 5 chemical changes are. 1) Tarnish, 2) Rust, 3) Dissolve, 4) Burn, 5) Bake.
Explanation:
cells, dna, chromosomes, body systems