Concerning the nitrogen cycle, which of these is not true? select one: a. it requires a number of different types of bacteria. b. plants can take in and use nitrogen from the air by using their leaves. c. ammonium in the soil is converted to nitrite by nitrite-producing bacteria and then nitrite is converted to nitrate by nitrate-producing bacteria. d. eventually, organic nitrogen becomes inorganic nitrogen again. e. human activities increase the nitrogen fixation rate.

Which sentence about particles in matter is true? a. atoms are present in solids and liquids but not in gases. b. the particles of matter are in constant motion. c. the same kinds of atoms are found in different elements. d. when a solid changes to a liquid, the sizes of the particles 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

An unknown substance has been shown to have weak covalent bonds. which of the following is most likely a property of this substance? a. high ph b. high conductivity c. low melting point d. low flammability