summer is likely to get much hotter than a person who is wearing a t-shirt. This is because the sweatshirt insulates the person, trapping heat inside.” What does the word insulates mean in the sentence above?

Answer is- Atoms of an element with the same mass number make up an isotope of the element. Different isotopes of the same element cannot have the same mass number, but isotopes of different elements often do have the same mass number, e.g., carbon-14 (6 protons and 8 neutrons) and nitrogen-14 (7 protons and 7 neutrons).