If a chemical change has taken place, which of these is most likely true? It's for science.

If 2g of an isotope has a half life of 7days, the half life of 1g of sample will be?

When an ionic bond forms between lithium (Li) and fluorine (F), which of the following occurs? F loses one electron. F loses two electrons. F gains one electron. F and Li share electrons.

How easy can water pass through granite?

Is this experiment okay for this question? If not, what would a good one be? 1. Design an experiment to verify that new substances are formed and heat is released or absorbed during a chemical reaction.

Which of the following is an example of a double-replacement reaction? A. 3K + AlCl3à 3KCl + Al B. KOH + HBr à KBr + H2O C. CH4 + 2O2à CO2 + 2H2O D. Cu + 2H2SO4à CuSO4 + SO2 + 2H2O

Each degree on the Kelvin scale equals: 1°C 10°C no relationship (different scale) 100°C

2C (s) + 2H2 (g) → C2H4 (g) : ΔH = + 52.4 kJ/mol Which statement about this reaction is correct?

A chemist dissolves 660. mg of pure hydroiodic acid in enough water to make up 300. mL of solution. Calculate the pH of the solution. Round your answer to 3 significant decimal places.

What type of radiation wave from the Sun does this graphic display? answer choices: x rays microwave visible ray infrared ray

What is the charge associated with each side of the HCl molecule?