How many valence electrons do the elements in column 2 have? 10 none 2 8

A change in the size, shape, or state of matter. chemical change physical change

What is the general rule for solutions? Unlike substances always dissolve in each other All substances dissolve in water Like dissolves like Solutes are always present in larger amounts than solvents

Which of the following is NOT a characteristic of solutions? Particles never settle on standing Particles can be separated by filtering Light passes through unchanged Particles are between $0-100$ nm in size

What 2 things are true about $CaCl_{2}$ D a it has ionic bonds b It is called Calcium (II) Chloride C It is called calcium chloride. d it has covalent bonds e it has metallic bonds f It is called calcium dichloride.

The strongest interactions between molecules of ammonia $(NH_{3})$ are A dipole-dipole. B polar covalent. C ionic bonds. D dispersion forces. E hydrogen bonds.

Compare a physical change to a chemical change? A physical change keeps the same composition A chemical change creates a new product A chemical change keeps the same composition A physical change creates a new product

4.3 Lab Lab is due AT THE END OF THIS PERIOD instructions: You are going to be modeling different reactions in a variety of ways. We will use different marker colors to represent different elements. Color Key: $Red=Hydrogen;\quad Black=Carbon;\quad Blue=Oxygen;$ $Green=Nitrogen;\quad Yellow=Sulfur;\quad Orange=Sxpgen;\\ Purple=Chlorine;\quad Pink=Potassium$ 1. $C+O_{2}\rightarrow CO_{2}$ $\square $ 7 $\square $ $\square $ disappointed $\square $ discussed $N_{2}+O_{2}\rightarrow N_{2}O_{5}$ $\square $ Write Unbalanced Reaction Here: $\square $ $\square $ $\square $ $N_{2}+H_{2}\rightarrow NH_{3}$ $\square $ Draw Unbalanced Reaction Here: $\square $ $\square $ disappointed $C_{2}+H_{2}\rightarrow C_{2}H_{6}$ $\square $ $\square $ $\square $ $\square $ 5. $CH_{4}\rightarrow C+H_{2}$ $\square $ iced Reaction Here: $\square $ $\square $ $\square $

Which of the following is an example of chemistry in everyday life? Leading a history book d. Balancing a checkbook Q Cooking food and watching it change color A Playing a video game

The electron configuration of an atom is \( 1 s^{2} 2 s^{2} 2 p^{6} \). The number of electrons in the atom is 3 10 8 6

2. When the elements are rearranged between the reactants and the products in the chemical reactions.what can you infer about the chemical and physical properties of the products?