I'll give a lot of points if you can help: How many C atoms are present in a 7.37 ng sample of quinine, C20H24O2N2? Note: 1 ng is one nanogram. Enter your answer in exponential notation, e. g. 1.23e20 for 1.23x1020. Do not include any units or words as part of your answer. Give your answer accurate to three significant figures. Molar masses (in g mol−1): H, 1.008 C, 12.01 N, 14.01 O, 16.00

Use the drop-down menus to answer each question. which runner finished the 100 m race in the least amount of time? which runner stopped running for a few seconds during the race? at what distance did anastasia overtake chloe in the race?

The identities of substances are the same before and after which type of change

Plz me ! 1 which of earths spheres contains most of its mass? a atmosphere b hydrosphere c geosphere* d biosphere 2 erosion and weathering are examples of which types of forces? a constructive forces b destructive forces* c gravitational forces d inertia-related forces 3 which of the following statements about earths atmosphere is true? a earths atmosphere contains 78% water vapor which is essentail to life b earths atmosphere contains 21% oxygen c earths atmosphere contains carbon dioxide which all life forms require d earths atmosphere allows radiation from the sun to pass through it and warm earths surface* 4 the strenght of the force of gravity between two objects is determined by which of the following factors? select all that apply a the messes of the objects* b the distance between the objects* c the volumes of the objects d the surface area of the objects 5 earth and moon are kept in there respective orbits due to the influence of a inertia b gravity c gravity and inertia* d neither gravity or inertia if you answer all questions right i will give