What is a compound?
a- a substance in which the atoms of two or more elements are combined together b-an atom with more neutrons than protons
c- a substance in which the atoms of three or more elements are combined together
d- an atom with more electrons than protons

Which symbols below represent the ions found in the glass of water ? a. oh- and h+ b. co2 and o2 c. o2 and h2 d. nh3- and h+

Put the following processes of protein synthesis in the correct order: - dna strands unwind and separate - mrna copies dna according to complimentary base pairing - trna's anticodons bring amino acids to the corresponding mrna codons - amino acids bind to each other making a protein - mrna leaves the nucleus - a stop codon is reached, the newly formed protein is released to go do its job for the cell

20 points and brainlist 1. london has suffered from terrible air pollution for at least seven centuries. why is the city so prone to its famous “london fog? ” what did london do to get rid of its air pollution? 2. why does air pollution cause problems in developing nations more than in developed ones?