1. The atomic number is equal to the number of protons in the nucleus, and the mass number is equal to the number of protons and neutros in the nucleus.
Therefore, to find the number of neutrons we must do mass number - atomic number, which equals 54.
Answer 1: a. 54
2. Atoms of a same element that have a different number of neutrons in the nucleus are called isotopes of an element.
Answer 2: d. Isotopes
3. Potassium has an electron configuration of , meaning that the first 3 shells are full, and that the last shell (4th one) has only 1 electron.
Answer 3: c. Shells 1, 2 and 3 are full and shell 4 has one electron.
4. An atomic bond isn't a specific bond, it's just a term. Polar covalent and non-polar covalent bonds are strong bonds, which leaves us with the hydrogen bonds, which are indeed the weakest bonds out there.
Answer 4: a. Hydrogen bond
Hope it helped,
BiologiaMagister
Answer:
The magnesium reacted with the oxygen in the air.
Explanation:
For argument’s sake, let’s say that the mass of magnesium oxide was 3 g and that of the oxide was 5 g.
The reaction was
magnesium + oxygen ⟶ magnesium oxide
Mass: 3 g 5 g
Mass of oxygen = 5 g – 3 g = 2 g
The 3 g of magnesium must have combined with 2 g of oxygen to form 5 g of magnesium oxide.
Answer:
I think that it's the temperature
Answer:
C. Cutting your hair
Explanation:
A physical change is one of the two types of changes in nature (the other being chemical change). A physical change does not affect the chemical composition of the substance(s) involved.
In this case, "CUTTING ONE'S HAIR" is an example of physical change because it involves the removal of the hair without altering the chemical composition of the hair. However, other examples given in the options of this question like digestion of food, getting a suntan (change in skin coloration), and growth in height all involve a change in the chemical nature of the parts involved, hence, they are examples of chemical changes.