How was the earth crust percentage determined?

This element is used to improve the conductivity of germanium. (A) K (B) Ga (C) Fe (D) Mg (E) Al

Which statement describes the general trends in electronegativity and first ionization energy as the elements in Period 3 are considered in order from Na to Cl? (1) Electronegativity increases, and first ionization energy decreases.

Which set of numbers gives the correct possible values of l for n = 2? 0 0, 1 0, 1, 2 0, 1, 2, 3

Ammonia react with phosphorus acid to form a compound that contains 28.2% of nitrogen 20.8%, phosphorus 8.1% of hydrogen 42.9%oxygen. Calculate the empirical formula of this compound

13. What salt results from the neutralization of phosphoric acid with potassium hydroxide?

Is it possible for a balloon with an initial internal pressure equal to 250.0 kPa to naturally expand to four times its initial volume when the temperature remains constant and the atmospheric pressure is 101.3 kPa?

How many atoms of gold (Au) are present in a sample of 2.5 mol Au? A. 1.5 * 1024 atoms Au B. 1.5 * 1023 atoms Au C. 4.2 * 1024 atoms Au D. 4.2 * 1023 atoms Au

what might cause the goldfish population to drop if the temperature moves out of its normal range? Name three things

Why must a chemistry experiments performed in a well ventilated room?

What kind of chemical bond does salt have?