Which of these substances are elements?

quartz

water

iodine

lead

silicon

silicone

20. An atom has a mass of 50 and 20 protons. How many neutrons does it have? Answer:

In a closed system, how will a decrease in pressure affect the following reaction: 2A (g) + 2B (g) ⇌ 2C (g) + 2D (g) ? A. Equilibrium will shift towards compound A. B. No change will occur. C. Equilibrium will shift towards compound D. D.

In correct order, what are the nitrogen bases in the initiation code for a peptide chain? A. adenine, thymine, and cytosine (ATC) B. adenine, cytosine, and thymine (ACT) C. cytosine, guanine, and thymine (CGT) D. thymine, adenine, and cytosine (TAC)

What happens when Aluminium metal is added to copper sulphate solution

There be shows an electric Can htbulb battery What cames electric energy through the citcuit? the wires OB the battery the fan OD the light bulb

Which of the following phases of matter takes the shape of its container and has definite volume? Question 1 options: plasma solid gas liquid

If you breathe normally you have about 0.11 moles of air in your lungs and a volume of 2.4 L. If you then take a deep breath all the way, you will have 0.27 moles of air in your lungs. How big will your lungs be?

What's the isotopic symbol for sodium

Which of the following would likely be part of an ionic bond? Choose all that apply. A. K+1 B. Cl2 C. F-1 D. Ne

Freud argued that a person was more likely to commit crime when what part of the personality wasn't fully developed?