Statements: (1) In the tripeptide Gly-Ala-Ser, the amino acid at the N-terminal end is Ser. (2) More than one polypeptide chain may be present in a conjugated protein but not in a simple protein. (3) In solution at physiological pH, the side chain of a polar basic amino acid bears a negative charge. a. All three statements are true. b. Two of the three statements are true. c. Only one of the statements is true. d. None of the statements are true.

the density(ratio between mass and volume as m/v) decreases from top to bottom in periodic table group as the size increases and nuclear charge decreases. but in periods density increases from left to right as atom size decreases and nuclear charge increases.

in 1783 cavendish was working with his hydrogen gas and found that when he burned it and condensed the vapor it was water. this was very significant since it disproved the greek theory of elements completely since water was not a simple substance but the product of two gases. it was lavoisier who hearing of the experiment gave cavendish's gas the name hydrogen ("water-producer") and added that hydrogen burned by combining with oxygen and that water was a hydrogen-oxygen combination.

explanation:

explanation:

let the different atoms be x and y. each with four protons and same mass will be represented as follows.

mass number is number of protons + number of neutrons.

            and  

since, it is given that one has a negative charge while the other is neutral. therefore, there will be increase in number of protons and the atom will be represented as follows.

according to periodic table, mass number of beryllium is 9 and it has atomic number 4 so, the atoms will be and .  

the protons and neutrons will be located inside the nucleus whereas the electrons will be revolving around the nucleus.  

air

in a tire you fill a tire with air

then a couple days later you check the air pressure in the tire

hope this mark me brainliest