<span>Scientist think convection currents are what cause earths plates to move. a convetion current is caused by the diffrence in the temperature, Mantle material close to the earths core is very hot. Mantle material near the lithosphere is cooler.</span>
A) part a is cell wall part b is chloroplast
The immune system, and the excretory system
(Honestly, all of them work to keep us 'healthy', but I believe these are the ones you're looking for)
The best answer is D.
The mass number of an element is the sum of the number of protons and the number of neutrons. Protons and neutrons both weigh about one atomic mass unit or amu.
The nucleus of an atom is made up of protons and neutrons. Both these two types of particles are almost the same size. Almost all the mass of an atom (99%) is in the nucleus. Atomic mass therefore is really a measure of the size of the nucleus.
Answer:
7) a. Absorbed: black surfaces absorb light, like in a playground.
b. Transmitted: when light falls on transparent objects, it is transmitted, goes straight through the object, like the clear glass of a window
c. Reflected: when light falls on a smooth, shiny object, it bounces off in one particular direction, like looking at the smooth surface of a lake