Baby Caitlen is about to turn one year old. She loves to play peek-a-boo and acts so surprised each time a hidden face appears behind her dad's hands. Why is she surprised?

The octet rule pertains to: a. only the noble gases. b. only groups 1A and 2A. c. elements in Groups 1A - 7A. d. all elements in the periodic table.

Complete the sentence. Select all that apply. The emission of a Beta particle has the effect of: decreasing mass by one unit increasing mass by one unit no change in mass adding a proton to the nucleus adding a proton of zero mass to the nucleus

Describe two human actions that cause water pollution.

In a coffee-cup calorimeter, 0.00500 mol of mg is reacted with enough hno3 to produce 100.0 ml of solution. the reaction is shown below: mg (s) + 2 hno3 (aq) → mg (no3) 2 (aq) + h2 (g) the temperature of the solution rose from 25.0°c to 30.5°c.

What is the difference between boyle temperature and critical temperature?

56 Explain, in terms of atomic structure, why the elements in Group 2 have similar chemical properties. 131

What must molecules do to react? a. Molecules must heat up b. Molecules must collide c. Molecules must expand to fill their container d. Molecules must interact with a catalyst

How many pictograms are in a gram?

Which type of signaling pathway uses second messengers because the hormone cannot pass through the plasma membrane? a.) amino acid based b.) lipid based

Why are the gases in the troposphere layer denser than the gases in the other layers?