Which of these measurements is expressed as three significant figures?

A. 0.0070 cm

B. 883.2 km

C. 4.20 g

D. 990, 000 mL

What is the force that occurs when two objects rub together

What would you use chromatography for?

A liquid is determined to be an acid or base depending on the type of (Blank) A. Electrons B. Protons C. Ions D. Elements E. Neutrons

Without a catalyst, a reaction may require very high temperatures in order to occur. How does a catalyst speed a reaction at low temperatures? It raises the amount of energy required to break chemical bonds.

How many electrons are transferred between the cation and anion to form the ionic bond in one formula unit of each compound? (1 electrons, 2 electrons, 3 electrons, 4 electrons) ? NaCICaSBaOKBrLiF

Are specimens the best source of DNA

Given the solubility, calculate the solubility product constant (ksp) of each salt at 25°c: (a) ag2so3, s = 4.6 * 10-3 g/l; (b) hg2i2, s = 1.5 * 10-7 g/l; (c) zn3 (po4) 2, s = 5.9 * 10-5 g/l.

Why does ionization energy tend to increase as you move across a period

Why does the rate of a reaction generally increase with increased temperature? (Choose all that apply) A. at higher temperatures, molecules are more likely to collide with each other in the correct orientation. B.

What is the wavelength of microwaves of 3.0x109 Hz frequency? c = 3.0x108 m/sec