During a lab activity, students were given samples of four different unknown elements. The students record their observations as shown in the table. Sample 1 Sample 2 Sample 3 Sample 4
shiny shiny reddish-brown colorless
high electrical

conductivity

low electrical

conductivity

low electrical

conductivity

low electrical

conductivity

solid at room temp. solid at room temp liquid at room temp. gas at room temp.
flattens when hit

with a hammer

breaks into pieces when hit with a hammer
splashes when hit

with a hammer

no effect when hit

with a hammer

boiling point:

882.9 °C
boiling point:

3265 °C
boiling point:

58.8 °C
boiling point:

-268.9 °C

Which of the following BEST identifies which element(s) in the table are metallic?

A.
Sample 1, because it is shiny and a good conductor of electricity

B.
Samples 1 and 2, because both samples are shiny and solid at room temperature

C.
Sample 2, because it is shiny and solid at room temperature

D.
Sample 3, because it is the only sample that is a liquid at room temperature

What is the relation between concentration of reactants and the rate of chemical reaction?

Use the drop-down menus to answer each question. which runner finished the 100 m race in the least amount of time? which runner stopped running for a few seconds during the race? at what distance did anastasia overtake chloe in the race?

98 points you will be galileo perform the experiment to determine if objects with different mass fall at the same, or different, rates in the air and in a vacuum. before you conduct your experiment, you need to form a hypothesis. a hypothesis is a prediction of what you think will happen in the experiment. the hypothesis is a statement that describes “if” a certain set of circumstances are present “then” there will be a specific result that will occur. record your hypothesis here: record the results from step one of the experiment (dropping the objects in the air): first trial: second trial: third trial: record the results from step two of the experiment (dropping the objects in a vacuum): first trial: second trial: third trial: did the experiment support your hypothesis? using the data from your experiment, describe why you believe your hypothesis was either proven or disproven. what forces were acting on the objects dropped in the air? what force was acting on the objects dropped in the vacuum? part two: comparing forces choose two forces and compare and contrast these forces. you must provide two ways that they are alike and two ways that they are different. you may make a list, write in paragraph form, or make a chart. choose two forces and compare and contrast these forces. these must be different forces than used in the prior question. provide two ways that they are similar and two ways that they are different. you may make a list, write it out, or make a chart.