Suppose you have 100 grams of a radioisotope with a half-life of 100 years. How much of the isotope will you have after 200 years?

Which of the following objects would float when placed in water? (Note: 1 mL 1 cm+3) * apple: density-0.7 g/m gold: density 19.3 g/mL iron: density-7.8 g/mL rubber: density-1.2 g/mL

Two chemical bonds unite three atoms into a molecule. Which types of bonds are they?

While David was riding his bike around the circular cul-de-sac by his house he wondered if the constant circle motion was having any affect on his tires. what would be the best way for David to investigate this?

What is the molar mass for the compound feso4?

One type of indigestion tablet contains magnesium hydroxide. This base neutralises stomach acid as shown by the balanced chemical equation Mg (OH) 2 + 2HCl → MgCl2 + 2H2O How does the pH in the stomach change after taking the tablets?

How do scientist know that atoms and molecules combine in well-ordered arrays?

Explain why potassium and argon react together

Which indicator will be the same color in hydrochloric acid as it is in pure water? 1. methyl orange 2. phenolphthalein 3. bromcresol green

Based on your knowledge of energy resources conservation, which of the following statements is true? a) Manufacturers can increase a light bulb's energy efficiency by using technology that decreases the amount of electromagnetic energy the bulb

Ammonia (nh3 (g), hf = - 46.19 kj/mol) reacts with hydrogen chloride (hcl (g), hf = - 92.30 kj/mol) to form ammonium chloride (nh4cl (s), hf = - 314.4 kj/mol) according to this equation: