Answer:
Electrons Can Donate - 0
Electrons Can Receive- 2
Valence - 2
Explanation:
The electronic configuration of oxygen is 
. Thus in the p-orbital there is deficiency of two electrons. Hence, it can receive/share electron but it cannot donate electrons. This makes oxygen as a good electron acceptor. Since there is a deficiency of two electrons in the outermost shell of oxygen, the valence of oxygen in thus -2
The most likely consequence of the widespread lack of bees is loss or reduction of food. Majority of food depends on pollination and bees are major pollinators in the ecosystem, playing an essential role in food production among different type of plants. Bee’s declining population is mostly associated to excessive use of pesticides or toxicants in industrial agriculture as well as presence of different parasites or pathogens and even climate change.
The role of the retina is to receive light that the lens has focused. It then converts the light into neural signals which get sent to the brain for visual recognition.
The diagram of water cycle includes the evaporation of water from water bodies. This is often expressed by an arrow or a bunch of arrows that arise from the water body and point towards the sky.
Some diagrams also symbolically show the evaporation process as water vapor that is symbolised with wavy curved arrows
