Answer:
1 and 3
Explanation:
The vertical columns (groups) of the periodic table are arranged such that all its elements have the same number of valence electrons. All elements within a certain group thus share similar properties.
Answer:
B) a substance's color and odor changed Explanation: A signal that a chemical change has occurred is when its odor (its smell) or its appearance has changed.
Answer:
Cobalt chloride
Explanation:
It is a molecule formed of one Cobalt atom, and two Chlorine atoms.
Answer:
True
Explanation:
Neutral solutions maintain a pH of 7. Water and human blood are great examples of neutral solutions. Acids mixed with bases can be neutralized and given a pH of 7.
Mass of solute ( m1 ) = 50.0 g
mass of solvent ( m2 ) = 150.0 g
Therefore:
m/m = ( m1 / m1 + m2 )
m/m = ( 50.0 / 50.0 + 150.0 )
m/m = ( 50.0 / 200 )
m/m = 0.25