Answer:
1. Rutherford did the scattering experiment and observed that some of the rays bounce back. He concluded that there is a mass in which positive charge is concentrated. This marks the discovery of nucleus.
2. J.J Thomson discovered electrons by conducting cathode ray experiment.
3. Dalton postulated that matter is made up of small particles caled atoms
Answer:
Option C = 1.72 mol
Explanation:
Given data:
Mass of KF = 100 g
Moles of KF = ?
Solution:
First of all we have to calculate the molar mass of KF.
Molar mass of KF = 39.0983 g/mol + 18.998403 g/mol
Molar mass of KF = 58. 0967 g/mol
Formula:
Number of moles = mass/molar mass
Number of moles = 100 g/ 58.0967 g/mol
Number of moles = 1.72 mol
Having a pH of 6.3 for a kiddie pool would be considered as acidic. You need to increase this value to keep it safe for use. The safest pH level would be from 7.2 to 7.4. This would be safe for the skin of the one who uses the pool. Hope this answers the question.
if 105 grams burns completely
therefore
105 ×22.4/48=49
False. A buffering solution consists of a WEAK acid such as CH3COOH, C5H5N, or ammonia. <span>A buffering solution resists pH change upon the addition of an acidic or basic components. It can neutralize little amounts of added acid or base, thus maintaining the pH of the solution relatively stable. The correct answer is letter "B. false"</span>