There are several things that can help scientists evaluate which category something belongs to. The similarity in features is one of them. If two skulls looked alike, they were probably species of the same evolutionary category. For example say humans and monkeys rather than humans and dogs.
Similarly fossils have helped scientists categorise species. Study of the chromosomes (in cases with available chromosomes) can help scientists figure out a lot about the subjects and categorise them.
An example of accurate but not precise would be 3 people weigh a 10g sample. the weights are 0g, 10g, & 20 grams. the scale is way off but the weights average to the right thing.
precise but not accurate would weighing a 10g sample 3 times and getting 5.5, 5.4, & 5.5. they'e all incredibly similar therefore precise but its nowhere near 10, so not accurate.
neither precise nor accurate would be 3 weights being 10, 20, &30. It averages wrong and is imprecise.
Ionic compounds are those compounds which form an ion or
dissociates into ions when placed in a solution. These compounds are made up of
a metal and non metal. From the choices, here are the ionic compounds:
na2so4
h2so4
cacl2
<span>ca3(po4)2</span>
Answer:
50
Explanation:
If you want a percent as a decimal so you can divide you must make it a decimal for example in your case it would be like this, 0.05, then all you do is divide 1,000 by 0.05
Answer: penetration is the ability of an electron in a given orbital to approach the nucleus closely. Shielding refers to the fact that core electrons reduce the degree of nuclear attraction felt by the orbital electrons. Shielding is the opposite of penetration. The most penetrating orbital is the least screening orbital. The order of increasing shielding effect/decreasing penetration is s<p<d<f.
Explanation:
The order of penetrating power is 1s>2s>2p>3s>3p>4s>3d>4p>5s>4d>5p>6s>4f....
Since the 3p orbital is more penetrating than the 3d orbital, it will lie nearer to the nucleus and thus possess lower energy.
