2). The farther a planet is from the sun, the longer it takes to orbit the sun. Mercury ... 88 days. Earth ... 365 days. Jupiter ... 12 years. Neptune ... 165 years.
3). Mercury & Venus ... no moons Earth - 1 Mars - 2 Jupiter - more than 65
4). Mercury ... cratered, no atmosphere Venus ... cratered, thick cloudy atmosphere Mars ... dry, cratered, slight atmosphere, like 1% or Earth's
Jupiter, Saturn, Uranus, Neptune We can't see any surface. If any of them even HAS a surface, it's thousands of miles under a thick atmosphere of methane gas.
5). Missing from the list
6). Here's a list from the biggest planet to the smallest one. The numbers in parentheses are the radius of the planet -- half of the diameter:
Jupiter (69,911 km / 43,441 miles) – 1,120% the size of Earth Saturn (58,232 km / 36,184 miles) – 945% the size of Earth Uranus (25,362 km / 15,759 miles) – 400% the size of Earth Neptune (24,622 km / 15,299 miles) – 388% the size of Earth Earth (6,371 km / 3,959 miles) Venus (6,052 km / 3,761 miles) – 95% the size of Earth Mars (3,390 km / 2,460 miles) – 53% the size of Earth Mercury (2,440 km / 1,516 miles) – 38% the size of Earth
7). At least seven of the planets rotate in the same direction. There's something different about one of them ... it may be Uranus but I'm not sure. You'll have to look this up.
8). Saturn has the famous rings, that you can almost see with only binoculars. Spacecraft sent to observe the outer planets have detected very thin rings around Uranus and Neptune.
9). Included in #6.
10). I don't have complete info. Generally, the closer the planet is to the sun, the hotter it is. But there are a few exceptions. I think Venus ... the second one from the sun, is actually hotter than Mercury.
11). Just about every language has its own name for each planet.
12). "Terrestrial" means "like Earth" ("Terra"). The terrestrial planets are the ones that have solid surfaces and are made of rock. Mercury, Venus, Earth, and Mars.
13). "Jovian" means "like Jupiter". Either no solid surface, or very small, inside a big deep gas ball. Jupiter, Saturn, Uranus, Neptune.
In the photoelectric effect, when an x-ray strikes on a metal surface, the energy is completely absorbed by the metal. If the energy would be equal to or more than work function of metal, electron ejects out. The kinetic energy of the electron which is ejected depends on the energy of the incident radiation and work function of the metal.
