An atomic physicist determines that an atom is composed of 8 positively charged particles and has a mass of 15 amu. which is the best conclusion that can be drawn? 1.the atom has 7 neutrons and 8 protons. 2. the atom has 7 electrons and 8 protons. 3. the atoms has 8 neutrons and 7 electrons. 4. the atoms has 8 electrons and 7 protons.

Adelivery truck leaves a warehouse and travels 2.60 km north. the truck makes a left turn and travels 1.25 km west before making another right turn to travel 1.40 km north to arrive at its destination. what is the magnitude and direction of the truck's displacement from the warehouse?

In positive numbers less than 1, the zeros between the decimal point and a non-zero number are blank significant

People with normal vision cannot focus their eyes underwater if they aren't wearing a face mask or goggles and there is water in contact with their eyes. in a simplified model of the human eye, the aqueous and vitreous humors and the lens all have a refractive index of 1.40, and all the refraction occurs at the cornea, whose vertex is 2.60 cm from the retina.with the simplified model of the eye, what corrective lens (specified by focal length as measured in air) would be needed to enable a person underwater to focus an infinitely distant object? (be careful-the focal length of a lens underwater is not the same as in air! assume that the corrective lens has a refractive index of 1.62 and that the lens is used in eyeglasses, not goggles, so there is water on both sides of the lens. assume that the eyeglasses are 2.05cm in front of the eye.)