would tearing aluminum foil be a physical change

Find the difference 18/19 - 17/19 A. 2/19 B. 8/19 C. 1/19 D. 9/19

How many grams of NaNO3 will precipitate if a saturated solution of NaNO3 in 200 g of water at 50°C is cooled to 20oC? Assume the following solubility values for NaNO3: 114.0g/100g H2O at 50oC; 88.0g/100g H2O at 20oC

A 0.100 M solution of chloroacetic acid 1ClCH2COOH2 is 11.0% ionized. Using this information, calculate 3ClCH2COO-4, 3H 4, 3ClCH2COOH4, and Ka for chloroacetic acid.

Which metals may be oxidized by H + under standard-state conditions? Ag + (aq) + e - → Ag (s) E° = 0.80 V Cu2 + (aq) + 2e - → Cu (s) E° = 0.34 V Sn2 + (aq) + 2e - → Sn (s) E° = - 0.14 V Zn2 + (aq) + 2e - → Zn (s) E° = - 0.76 V

What type of ion forms when an atom loses electrons? a. neutral b. positive c. negative d. possibly positive or negative?

What quantity of heat is needed to raise the temperature of 5.0g of a substance from 20 c to 30 c if the specific heat?

Compare mechanical energy and thermal energy.

How many covalent bonds can each carbon atom form?

Hich element is likely to be the most brittle? a. selenium b. cobalt c. platinum d. zinc

What units should they have used in order to make the correct conversion