A Mars rover has collected and analyzed several samples from the surface and atmosphere of Mars. NASA has processed most of the data but is looking for help in identifying two of the remaining elements from the samples. They know that both elements are main group elements belonging in either Group 2 or Group 18. Group 2 elements are highly reactive, while Group 18 elements are unreactive. Group 2 elements are also solid at room temperature, while Group 18 elements are gases at room temperature. The following information about unknown Element J and unknown Element Q has just arrived for you to examine. Based on the evidence, write a scientific explanation to justify the periodic table group in which the elements belong. Element JElement Q Mass0.5 g1.2 g Physical State at Room Temperature SolidGas Electrical Conductivity GoodNone Reaction with Oxygen* Yes (forms XO)No Reaction with Chlorine* Yes (forms XCl 2 )No

In a thunderstorm, charge builds up on the water droplets or ice crystals in a cloud. thus, the charge can be considered to be distributed uniformly throughout the cloud. for the purposes of this problem, take the cloud to be a sphere of diameter 1.00 kilometer. the point of this problem is to estimate the maximum amount of charge that this cloud can contain, assuming that the charge builds up until the electric field at the surface of the cloud reaches the value at which the surrounding air breaks down. this breakdown means that the air becomes highly ionized, enabling it to conduct the charge from the cloud to the ground or another nearby cloud. the ionized air will then emit light due to the recombination of the electrons and atoms to form excited molecules that radiate light. in addition, the large current will heat up the air, resulting in its rapid expansion. these two phenomena account for the appearance of lightning and the sound of thunder. take the breakdown electric field of air to be eb=3.00ă—106n/c. part a estimate the total charge q on the cloud when the breakdown of the surrounding air is reached. express your answer numerically, to three significant figures, using ďµ0=8.85ă—10â’12c2/(nâ‹…m2) .

Pl asaaap ! match the term to the correct description. a type of wave that transfers energy where the particles in the medium move perpendicular to the direction in which the energy is traveling. a type of wave that transfers energy where the particles in the medium move parallel to the direction in which the energy is traveling. movement that is back and forth, like an equal sign = a type of wave that transfers energy where the particles in the medium move in a circle motion while the energy travels left or right. movement that is like a t transfers energy from one location to another 1. wave 2. parallel movement 3. perpendicular movement 4. transverse wave 5. longitudinal wave 6. surface wave

14. a body is projected with velocity vi from a.at the same time another body is projectedvertically upwards from point b withvelocity v2 lies vertically below the highestpoint. both the bodies collide thenv2÷v1is