Answer: Hydrogen and Helium
Explanation: Hydrogen is made from from one proton and one electron, making them one of the simplest forms of elements in the universe. Combining hydrogen atoms creates helium, the second most common element in the Universe.
The mass of 254 mL of water is 254 g. Since the density of water is 1g/mL, we can simply multiply the density 1g/mL by 254 mL of water and get 254 g as our answer. Since mL is in the numerator and denominator, mL cancels out and we are left with g only.
Explanation:
The number of protons in an atom is the atomic number.
Mass number is the number of protons plus neutrons in an atom.
Mass number = number of protons + number of neutrons
Atomic number = number of protons
Atomic number gives the symbol of the element
Number Number Atomic Mass Symbol
Protons neutrons Number Number
A 7 B 15 C
D E 26 56 F
A, number of protons = B
Mass number = protons + neutrons
15 = protons + 7
Protons = 15 - 7 = 8
Atomic number 8 is for oxygen = C
Atomic number = number of protons = D = 26
Number of neutrons ;
E = Neutrons = mass number - protons = 56 - 26 = 30
Atomic number 26 is for Iron = F
An ionic bond is a type of chemical bond formed through an electrostatic attraction between two oppositely charged ions. Ionic bonds are formed between a cation, which is usually a metal, and an anion, which is usually a nonmetal. A covalent bond involves a pair of electrons being shared between atoms.
