Write the complete symbol, including mass number and atomic number, for each atom.

Question

Write the complete symbol, including mass number and atomic number, for each atom.

1. contains 28 protons and 30 neutrons:
2. contains 22 protons and 21 neutrons:
3. contains 15 electrons and 19 neutrons
4. an oxygen atom with 10 neutrons:
5. a chromium atom with a mass number of 54:

Answer 1

1). 28 protons defines the element as Ni (nickel). The mass number is 28 + 30 = 58.

Symbol: ⁵⁸₂₈Ni

2). 22 protons defies the element as titanium (Ti). The mass number is 22 + 21 = 43.

Symbol: ⁴³₂₂Ti

3). 15 electrons means it also has 15 protons (assuming it is a neutral atom). This defines the element as phosphorous (P). The mass number is 15 + 19 = 34.

Symbol: ³⁴₁₅P

Hopefully you will be able to do the remaining 2 questions.