The atomic number of boron is 5. what is the mass number of a boron atom with 4 neutrons?

two people start out 100 meters apart from each other and start moving towards each other at the same time. One person is moving at half the speed of the other person and they meet after 25 seconds of travel time. what was the speed of each person.

A cell with an extracellular sodium ion concentration of 50mm and an intracellular sodium ion concentration of 100mm needs to move sodium from outside the cell into the cell. which of the following mechisms is likely involved.

The chicken wing is made up of only 1 type of tissue. true or false?

Which list of symbols represents nonmetals, only? (1) B, Al, Ga (2) Li, Be, B (3) C, Si, Ge (4) P, S, Cl

I don't know how to do this chemistry assessment over empirical formula

Sarah heated some orange coloured crystals in a test tube. The crystals turned green and fizzed. After the fizzing stopped, the test tube was allowed to cool. A green powder was left in the tube.

In which orbital does an electron in a bromine atom experience the greatest effective nuclear charge?

Kool-Aid is made up of sugar (C6H12O6), food coloring, and water. It is an example of a (n) element heterogeneous mixture homogeneous mixture compound

A laboratory experiment requires 250 millimeters of water for boiling. It also requires 100 millimeters of water for a cooling process.

Which set of procedures and observations indicates a chemical change? A) Ethanol is added to an empty beaker and the ethanol eventually disappears. B) A solid is gently heated in a crucible and the solid slowly turns to liquid.