Potassium is placed where it is based on its properties and it's reactivity. It's also placed there based on it's atomic number.
Answer:
A chemical change
Explanation:
The marshmallow turning brown and bubbling implies that a chemical change has taken place.
For chemical changes to occur, we observe any of the following:
- a new kind of matter is formed.
- it is always accompanied by energy changes
- the process is not easily reversible
- it involves a change in mass
- requires considerable amount of energy.
ii. Two signs that shows a chemical change has taken place is that:
- bubbles are being formed as it is roasted and it implies that new substances have been formed.
- also, significant amount of heat energy is supplied for the roasting.
An ionic compound is made up of a metal and a nonmetal. This eliminates answer choice A, C, and D because both of the elements listed are nonmetal.
Your correct answer is B) One atom of calcium and two atoms of chlorine. This is because calcium is a metal, and chlorine is a nonmetal.
Balance the equation first:
2 Fe+6 HNO3→2 Fe(NO3)3+3H2
Then calculate mass of Iron :
4.5×3.0×3.5 cm3(1 mL1 cm3)(7.87 g Fe1 ml)=371.86 g Fe
Now use Stoichiometry:
371.86 g Fe×(1 mol Fe55.85 g Fe)×(6 mol HNO32 mol Fe)=19.97 mol HNO3
Convert moles of nitric acid to grams
19.97 mol HNO3×(63.01 g HNO31 mol HNO3)=1258.3 g HNO3
