I think thee correct answer from the choices listed above is option D. <span>When a physical change in a sample occurs, composition of the sample does not change. It stays the same. Also, the properties of the sample will still be the same. Hope this answers the question.</span>
Answer:
what kind of math is this
Explanation:
1=c 2=a 3=b
i hope these answer your questions
The atomic number for Pb is 82
∴ Pb has 82 protons and 206-82 = 14 protons
The actual mass of Pb nuclei is
=(82 × mass of the proton) + (124 × mass of neutron)
=(82× 1.00728) + (124 × 1.008664) amu
= 207.6713 amu
The mass of lead which is given is 205.9744 amu
∴mass defect is
m = 207.6713 - 205.9744 = 1.6969 amu
=1.6969 × 1.66054 × 10⁻²⁷kg
=2.818 × 10⁻²⁷kg
The binding energy is E = mc²
C is the speed of light in vacuum = 2.9979 × 10⁸m/s
∴ E = 2.532 × 10×⁻¹⁰ J/mol
= 2.532 × 10⁻¹⁰ × 6.023 × 10²³ J/mol
= 1.53811 × 10¹⁴ J/mol
i. When an acid reacts with metal, a salt and hydrogen are produced:
ii. When oxygen and metal react, metal oxide forms also known as rust
iii. metal and water produce hydrogen gas