Answer:
Stars are made of very hot gas. This gas is mostly hydrogen and helium, which are the two lightest elements. Stars shine by burning hydrogen into helium in their cores, and later in their lives create heavier elements.Stars are huge celestial bodies made mostly of hydrogen and helium that produce light and heat from the churning nuclear forges inside their cores.
Hello,
Here is your answer:
The proper answer to this question is option D "wood is burned". Its a chemical change because its changing forms wood to ash.
Your answer is D.
If you need anymore help feel free to ask me!
Hope this helps!
Answer:
B
Explanation:
Solar power takes in light and turns it into a usable energy. if used in a vehicle that would take light energy and transform it into mechanical energy.
The rays of the sun will go directly to the trees, then
trees take up light that absorbs light energy which converting light to
chemical potential energy kept in chemical bonds. And when the trees cut into
woods and burnt it, it will convert to thermal energy.
Answer:
Volume of HNO₃ required = 140 mL
Explanation:
Given data:
Molarity of HNO₃ = 0.563 M
mass of BaCO₃ = 7.83 g
Volume of HNO₃ = ?
Solution:
First of all we will write the balance chemical equation
2HNO₃ + BaCO₃ → Ba(NO₃)₂ + H₂O + CO₂
Number of moles of BaCO₃ = mass / molar mass
Number of moles of BaCO₃ = 7.83 g / 197.34 g/mol
Number of moles of BaCO₃ = 0.04 mol
Now we compare the moles of BaCO₃ and HNO₃ .
BaCO₃ : HNO₃
1 : 2
0.04 : 2×0.04 = 0.08 mol
Volume of HNO₃ required = number of moles / Molarity
Volume of HNO₃ required = 0.08 mol / 0.563 mol/L
Volume of HNO₃ required = 0.14 L
0.14 × 1000 = 140 mL
