If you forget to dry off a bread knife and when you washed it and reddish brown spots appeared on it would that be physical or chemical change

Which element has 3 valence electrons in the 4d sublevel? A. V B. Nb C. Cu D. Tl

Which of the following changes are chemical changes? a. Water is frozen. b. Water is heated up. c. Gasoline is burned. d. Gasoline is evaporated. e. Water is boiled.

A proton is a hydrogen atom without its electron? True False

Which atom's ionization energy is greater than that of phosphorus (P) ?

Hi! Hope ur doing good my question is:What is the densest layer of earth?

What is the molarity of a solution that has 548 grams of HCl dissolved in 1.50 l water?

Steve puts some cheddar cheese in a pan on the stove and starts to melt it. After a little while, there is a layer of oil floating on top of the cheese. From the way the cheese melted, Steve knows it is a A Element B Solid C Mixture D Pure Substance.

Which experimental feature of the MALDI-MS technique allows the separation of ions formed after the adduction of tissue molecules? A) Distance travelled by ions depends on the ion charge. B) Velocity of ions depends on the ion mass-to-charge ratio.

Which temperature is required for the cell potential to be the standard cell potential? A) - 273°C B) 100°C C) 25°C D) 0°C

1. the purpose of the aqueous solutions in a galvanic cell is to? a. provide ions to be oxidized and reduced b. provide a path for the free flow of electrons c. maintain charge balance in the cell d. correct any volume changes in the cell 2.