Maria and jane set up a lemonade stand one summer to earn money for a trip to the beach. they noticed that the hotter the day, the more glasses of lemonade they sold. they mixed up the lemonade exactly the same way every day: the same amount of sugar, lemon juice, and water. they added ice to the glass when they poured the drink. they always used the same size glass. they decided to chart their sales in order to figure out how much lemonade to make each day, using the weather forecast as their guide. identify the independent, dependent, and controlled variables in the girls' experimental data.

CONTROLLED VARIABLE: glass size, amount of sugar, amount of lemon juice, water used, timing of adding ice

DEPENDENT VARIABLE: number of glasses sold

INDEPENDENT VARIABLE: daily temperature

Explanation: I had two attempts and the first one showed me the answer (USA test prep)

you need to take a look at the periodic system in order to sort these elements into pairs that would most likely exhibit similar chemical properties. first, you need to find elements that are found in the same group (groups are vertical in the periodic system), and then to see whether they have the same valence number. if they meet these criteria, they will have similar properties.

the first pair: ne (neon) and kr (krypton), are noble gases found in group 8

the second pair: li (lithium) and k (potassium), found in group 1

the third pair: s (sulfur) and te (tellurium), found in group 6

the answers are

c and c