1. Which of the following pairs of atoms are isotopes?

a) K-39 and K-40

c) C-12 and N-14

b) F-10 and Ne-10

d) H-2 and He-2

An 8.50 grams block of aluminum is heated with 54.98 kJ of energy. The temperature changed from 22.8 C to 94.6 C. What is the specific heat capacity of aluminum?

The process in which a large atom is split into two smaller atoms and releases energy is called

Write the measurement 0.00860 km in scientific notation using the correct amount of significant figures

Why is it better to use several trials of a titration rather than one trial to determine the concentration of a solution of unknown concentration?

A buffer is formed by mixing 100 ml of 0.1 m nh4cl with 50 ml of 0.3 m nh3. to this solution 13 ml of 0.1 m naoh is added. what is the approximate ph of the new solution after neutralization? assume a kb of 1.8 * 10-5 for the weak base. 1. 4.62 2. 4.

In the synthesis reaction, the white powder produced is magnesium oxide (mgo, mm = 40.3 g/mol). how many moles of magnesium oxide were formed (number of moles = mass (g) / molar mass (g/mol)) ? choose the closest answer. a. 0.21 moles b. 0.

Which of the following is the most likeley example of an favorable mutation A. A mutation that makes a rabbit able run faster B. A mutation that changes the rabbit's fur to bright orange C. A mutation that changes the color of the rabbit's eyes D.

Which of these mole ratios is possible for this reaction? FeCl3 + 3NaOH → Fe (OH) 3 + 3NaCl 1:1 1:3 3:1 2:3

The chemical equation for reduction of phosphorite Ca3 (PO4) 2

Synthesize What environmental effects are shared by all fossil fuels?