Help guys plz help me especially with 2 and 3

Based on the law of conservation of energy, which statement is false? answer- energy is lost when machines dont work right

According to the vsepr theory what is the shape of a molecule that has a central atom valence three other items with no lone pairs of electrons

Sally is making a model of a magnesium atom with an atomic mass number of 24 for her chemistry class. she has foam balls for the protons, neutrons, and electrons. she has added 6 neutrons to her model so far. how many more neutrons does she need to add to complete her neutral atom of magnesium?