How are protons in the nucleus of an atom able to stay close to one another even though they have the same charge?
Protons are able to stay close to one another in the nucleus of an atom because of strong force. This force (strong force) is greater than the force of the electromagnetic force.
Each element has two numbers. What is the top number? What is the bottom number?
The top number, on the periodic table, of an element represents the atomic number of the element, and the bottom number of the element represents the atomic mass of the element.
What is the mass number of an atom that has 3 protons and 4 neutrons?
ANSWER: 4
3 protons plus 4 neutrons gives a mass number of 7.
The electronic structure 2,5 is for which of the following elements?
ANSWER: 4. Nitrogen.
When particles in a solid are arranged in a regular pattern, they form what we call a:
ANSWER: 3 Crystal
Compare protons and neutrons.
What are protons? What are neutrons?
Protons are positively charged particles in the nucleus of an atom.
Neutrons are neutral charged (no charge) particles that are located in the nucleus of the atom.
Using the periodic table, determine which two groups have highly reactive metals.
The two groups that have highly reactive metals are the alkaline metals (Group 1) and the alkali Earth metals (Group 2).
Which of the elements below will have the same number of electrons in its outer shell as the atom shown?
ANSWER: 4.
Both potassium and the atom of lithium shown are in group I (1) of the periodic table and have one electron in their outer shells.
To which period does the element with the electronic configuration 2,8,7 belong?
ANSWER: 3. Three numbers in the electronic configuration means that this element is in the third period.
The diagram shows the changes in state of water (H2O). What is the process Y called?
What would happen to a nucleus containing two or more protons if the strong force were absent?
If there were two or more protons in the nucleus of an atom and no strong force the protons will repel from each other causing the nucleus to fly apart.
Of the gases oxygen, argon, chlorine, and neon, which would be the two most chemically reactive?
Of those gases listed, the most reactive ones will be oxygen and chlorine because the gases neon and argon are noble gases and are non-reactive.
Which of the following statements is/are correct?
(a) Protons have a charge of -1.
(b) Neutrons have no charge.
(c) An electron has negligible mass compared to the mass of a neutron.
ANSWER: 2
Which of the elements shown in the periodic table has 2 electrons in its outer shell?
ANSWER: 4. Calcium
Which one of the following statements is correct?
ANSWER: 2
What is an atom’s mass number equal to?
The atomic mass is equal to the number of protons and neutrons in the nucleus of an atom. (The number of electrons is relatively negligible compared to the mass of protons and neutrons)
Is it possible to have carbon atoms with different numbers of protons? Explain.
A carbon atom cannot have different numbers of protons in the nucleus of the atom because when the number of protons change, then the atomic number will change, which means the element will change.
The period in which an element is located gives us
ANSWER: 1. the number of electron shells that the electron has.
When the temperature of a liquid is increased a little, what happens to its particles?
ANSWER: 3 They start vibrating more
There are many videos online which claim cats are liquid. They claim this because cats appear to:
A. Take the shape of their container
B. Float in the air
C. Move without any force acting upon them
A. Take the shape of their container
Discussion time:
IS A CAT A LIQUID?
Explain why hydrogen is unique
Hydrogen is unique because it does not fit into the characteristics of any one group in the periodic table.
The diagram on the right shows the structure of an atom. What are the parts labelled A and B?
ANSWER: 1. A = electron, B = nucleus.
What is the charge on an electron?
ANSWER: 2. Minus one.
The melting point of H2O is
ANSWER: 0 degrees Celcius
Which one of the following is not a property of a gas?
ANSWER: 4, definite volume