Moving from left to right across a row of the periodic table, which of the following values increases by exactly one from element to element?
a. isotope number
b. atomic number
c. atomic mass unit
d. mass number

How do forces between particles in gases compare to forces in the other states of matter? o a. the forces in gases are stronger than forces in solids but weaker than forces in liquids. o b. the forces in gases are weaker than forces in solids but stronger than forces in liquids. o c. the forces in gases are weaker than forces in solids and liquids. o d. the forces in gases are stronger than forces in solids and liquids. submit

Agroup of students is studying convection current. they fill two identical balloons with the same amount of helium. one balloon is placed in a freezer and the other is in an area with warm air. after 10 minutes, the balloon are released from a height of 1 meter. which of the following to the students most likely observe? a) the warm balloon expands and rises. the cold balloon shrinks and sinks b) the balloon both rise. the cold balloon is larger than the warm balloon c) the cold balloon expands and rises. the warm balloon shrinks and sinks d) the balloon rise at the same rate. both balloons are the same size

The chart shows the bid provided by four contractors to complete a job. which contractor is the most cost-effective?