| An atom contains dense (1) surrounded by shells of (2) | 1. Nucleus
2. Electrons |
| What two nucleons make up the nucleus? | Protons and Neutrons |
| Each Electron shells is a certain distance from nucleus at its own particular | Energy level |
| Describe the charges and relative mass of each subatomic particle present | Electrons have a negative charge , and mass 1/1836
Protons have a positive charge, and mass 1
Neutrons are uncharged , and mass 1 |
| The atomic number can be known as this, and what is the atomic number | Atomic/ Proton number is the number of protons in the nucleus |
| What does every atom of the same element have in common? | Every atom of the same element has the same Atomic number |
| Mass number is also known as this, what is the mass number | Mass number ( nucleon number) is the number of protons plus the number of neutrons in the nucleus of an atom |
| What are isotopes? | Isotopes are atoms of the same element with different mass number. |
| Why do Isotopes of particular elements have same chemical properties, but slightly different physical properties | Isotopes of particular elements have same chemical properties because they have same number of electron. They have slightly different physical properties, because they have different number of neutrons |
| What are radioisotopes used for? | To check leaks in oil or gas pipelines |
| How many protons, neutrons and electron, are there in neutral atoms? | In neutral atom, number of positively charged protons in nucleus equals number of negatively charged electrons outside , nucleus |
| What are ions | Ions are charged particles formed by the loss or gain of electrons from atom of group of covalently bonded atoms |
| When are positive ions formed | When 1 or more electrons are lost |
| When are negative ions formed | When 1 or more electron is gained |
