K12 chemistry unit assessment: chemical bonding,

electrostatic forces in ionic bonds hold which of the following together? 1. He atoms in helium gas 2. Na + and Br - in NaBr 3. Fe atoms and localized electrons in iron

Is utensils a substance homogeneous mixture or heterogeneous mixture

Which parts of the amino acids X and Y are involved in the formation of a peptide bond? (N-terminus) XY (C-terminus)

Decide which element probably formed a compound with hydrogen that has a chemical formula most and least similar to the chemical formula of the compound formed by hydrogen and nitrogen

What is the tyndall effect

The strongest attractive forces between molecules of Cl 2 are dispersion forces

Which of the following represents a chemical change? Bending a wire Freezing of water Fireworks exploding Melting of a wax candle

5.00 L of a gas is collected at 100K and then allowed to expand to 20.0 L. What must the new temperature be in order to maintain the same pressure? A. 400 °C B. 127 °C C. 223 °C D. 627°C

Before the initial explosion was the matter hot or cold

Which of the following atoms has seven valence electrons? chlorine (Cl) nitrogen (N) manganese (Mn) oxygen (O)

A.) During an experiment, a student adds 2.90 g of CaO to 400.0 mL of 1.500 M HCl. The student observes a temperature increase of 6.00 °C. Assuming the solution/'s final volume is 400.0 mL, the density if 1.00 g/mL, and the heat capacity is 4.