1.
What is the chemical symbol for calcium?
Correct Answer
C. Ca
Explanation
The chemical symbol for calcium is Ca. Chemical symbols are used to represent elements in the periodic table, and Ca is the symbol specifically assigned to calcium.
2.
What is the atomic mass of phosphorus?
Correct Answer
B. 31
Explanation
The atomic mass of an element is the average mass of all the isotopes of that element, taking into account their relative abundance. Phosphorus has several isotopes, with atomic masses ranging from 28 to 34. The most common isotope of phosphorus, phosphorus-31, has an atomic mass of 31. Therefore, the correct answer is 31.
3.
What type of element is Potassium?
Correct Answer
A. Metal
Explanation
Potassium is a metal because it is a highly reactive alkali metal that belongs to Group 1 of the periodic table. Metals generally have properties such as high electrical and thermal conductivity, luster, malleability, and ductility. Potassium exhibits these characteristics, making it a metal.
4.
A positively charged subatomic particle is?
Correct Answer
A. Proton
Explanation
A positively charged subatomic particle is a proton. Protons are found in the nucleus of an atom and have a positive charge. They are one of the fundamental particles that make up an atom, along with neutrons and electrons. Protons have a mass number of 1 and a charge of +1.
5.
The atom oxygen has a neucleon number of 16 and a proton number of 8. what is the number of neutrons in the oxygen atom?
Correct Answer
C. 8
Explanation
The number of neutrons in an atom can be calculated by subtracting the number of protons (proton number) from the total number of nucleons (nucleon number). In this case, the nucleon number of oxygen is given as 16 and the proton number is given as 8. Therefore, the number of neutrons can be calculated as 16 - 8 = 8.
6.
An atom has very little empty space.
Correct Answer
B. False
Explanation
An atom actually has a significant amount of empty space. The majority of an atom's volume is occupied by its electron cloud, which consists of negatively charged electrons orbiting around a positively charged nucleus. The electrons are constantly moving, and the space between them and the nucleus is relatively large compared to the size of the particles themselves. Therefore, an atom is not solid and does have empty space within it.
7.
This subatomic particle has a negative charge.
Correct Answer
B. Electron
Explanation
The electron is a subatomic particle that carries a negative charge. It is found outside the nucleus of an atom and is responsible for the flow of electricity. Neutrons have no charge, protons have a positive charge, and isotopes are variations of an element with different numbers of neutrons. Therefore, the correct answer is electron.
8.
This subatomic particle has a positive charge.
Correct Answer
A. Proton
Explanation
A proton is a subatomic particle that carries a positive charge. It is found in the nucleus of an atom, along with neutrons. Electrons, on the other hand, carry a negative charge and orbit around the nucleus. Neutrons have no charge and also reside in the nucleus. Therefore, the correct answer is proton.
9.
How many neutrons does an atom with an atomic number of 23 and a mass number of 51 have?
Correct Answer
B. 28
Explanation
The atomic number of an atom represents the number of protons in its nucleus. The mass number represents the total number of protons and neutrons in the nucleus. To find the number of neutrons, we subtract the atomic number from the mass number. In this case, the atom has an atomic number of 23 and a mass number of 51. Subtracting 23 from 51 gives us 28, which is the number of neutrons in the atom.
10.
Electrons are found:
Correct Answer
B. Outside nucleus
Explanation
Electrons are found outside the nucleus. According to the Bohr model of the atom, electrons occupy specific energy levels or orbitals surrounding the nucleus. These energy levels are organized into electron shells, with the electrons in the outermost shell being the most loosely held by the nucleus. These outer shell electrons are involved in chemical reactions and bonding with other atoms, giving rise to the various properties of elements. Therefore, it is correct to say that electrons are found outside the nucleus.
11.
The ? and ? are found in the nuclues.
Correct Answer
C. Protons and neutrons
Explanation
Protons and neutrons are found in the nucleus of an atom. Protons have a positive charge, while neutrons have no charge. Electrons, on the other hand, are found outside the nucleus and have a negative charge. Therefore, the correct answer is protons and neutrons.
12.
These particles make up the mass of an atom.
Correct Answer
A. Protons and neutrons
Explanation
Protons and neutrons are the particles that make up the mass of an atom. Protons have a positive charge and are located in the nucleus of an atom, while neutrons have no charge and are also found in the nucleus. Electrons, on the other hand, have a negative charge and are located in energy levels outside the nucleus. While electrons contribute to the overall charge of an atom, they have negligible mass compared to protons and neutrons. Therefore, protons and neutrons are the particles responsible for the majority of an atom's mass.
13.
Atoms are arranged in the periodic table according to increasing numbers of?
Correct Answer
C. Protons
Explanation
Atoms are arranged in the periodic table according to increasing numbers of protons. The number of protons in an atom determines its atomic number, which is a unique identifier for each element. The periodic table is organized in such a way that elements with similar properties are grouped together. As the atomic number increases from left to right and from top to bottom in the periodic table, the number of protons in the atoms also increases. This arrangement allows scientists to easily identify and study the properties of different elements.
14.
The symbol for sodium is?
Correct Answer
D. Na
Explanation
The correct symbol for sodium is Na.
15.
An atom has very little empty space.
Correct Answer
B. False
Explanation
Atoms actually have a lot of empty space. They consist of a small, dense nucleus surrounded by a cloud of electrons. The nucleus contains protons and neutrons, which are tightly packed together, but the electrons orbiting around the nucleus are much smaller and occupy a larger volume. This means that the majority of an atom's volume is empty space. Therefore, the statement "An atom has very little empty space" is false.
16.
The number of protons in an atom is known as the?
Correct Answer
B. Atomic number
Explanation
The atomic number of an atom refers to the number of protons it contains. Protons are positively charged particles found in the nucleus of an atom. The atomic number determines the element to which an atom belongs, as each element has a unique number of protons. Therefore, the correct answer is "atomic number."
17.
This subatomic particle has a negative charge.
Correct Answer
B. Electron
Explanation
The electron is a subatomic particle that carries a negative charge. It is found outside the nucleus of an atom and is involved in various chemical reactions and electrical conductivity. Neutrons have no charge, protons have a positive charge, and isotopes are atoms of the same element with different numbers of neutrons. Therefore, the correct answer is electron.
18.
This subatomic particle has a positive charge.
Correct Answer
A. Proton
Explanation
A proton is a subatomic particle that carries a positive charge. It is found in the nucleus of an atom along with neutrons. Electrons, on the other hand, carry a negative charge and orbit around the nucleus. Neutrons have no charge and are also found in the nucleus. Therefore, the correct answer is proton.
19.
How many neutrons does an atom with an atomic number of 23 and a mass number of 51 have?
Correct Answer
B. 28
Explanation
The atomic number represents the number of protons in an atom, which in this case is 23. The mass number represents the total number of protons and neutrons in an atom, which is 51. To find the number of neutrons, subtract the atomic number from the mass number. Therefore, the atom has 28 neutrons.
20.
Electrons are found?
Correct Answer
B. Outside nucleus
Explanation
Electrons are found outside the nucleus. This is because electrons are negatively charged particles and are attracted to the positively charged protons in the nucleus. They orbit the nucleus in specific energy levels or shells, forming an electron cloud around the nucleus. The arrangement of electrons in these energy levels determines the chemical properties and behavior of an atom.
21.
The ? and ? are found in the nucleus.
Correct Answer
C. Protons and neutrons
Explanation
Protons and neutrons are found in the nucleus of an atom. Electrons, on the other hand, are found outside the nucleus in the electron cloud. Therefore, the correct answer is protons and neutrons.
22.
These particles make up the mass of an atom.
Correct Answer
A. Protons and neutrons
Explanation
Protons and neutrons are subatomic particles found in the nucleus of an atom. They are responsible for the mass of an atom. Protons have a positive charge, while neutrons have no charge. Electrons, on the other hand, are negatively charged particles that orbit around the nucleus. Although electrons also contribute to the overall structure of an atom, they have negligible mass compared to protons and neutrons. Therefore, the correct answer is protons and neutrons.
23.
The element chlorine has an electron configuration of 2,8,7. It is in which group and period?
Correct Answer
B. Group 17 and period 3
Explanation
The electron configuration of chlorine, 2,8,7, indicates that it has 17 electrons. The number of electrons in the outermost energy level is 7, which corresponds to group 17 on the periodic table, also known as the halogens. The period number is determined by the highest energy level that contains electrons, which in this case is the third energy level. Therefore, chlorine is in group 17 and period 3.
24.
Atoms are arranged in the periodic table according to increasing numbers of?
Correct Answer
C. Protons
Explanation
Atoms are arranged in the periodic table according to increasing numbers of protons. The number of protons in an atom determines its atomic number, which is a unique identifier for each element. The periodic table is organized in such a way that elements with similar properties are placed in the same column, known as a group. As the atomic number increases from left to right and from top to bottom in the periodic table, the number of protons also increases, resulting in a systematic arrangement of elements.
25.
The symbol for sodium is?
Correct Answer
D. Na
Explanation
The correct answer is Na because Na is the chemical symbol for sodium. The other symbols listed, S, N, and So, do not represent sodium.
26.
Aluminium has _______ electrons.
Correct Answer
13
Explanation
Aluminium has 13 electrons because the atomic number of aluminium is 13, which indicates the number of protons and electrons in an atom. Since atoms are electrically neutral, the number of electrons must equal the number of protons.
27.
What is the atomic number for hydrogen?
Correct Answer
A. 1
Explanation
The atomic number for an element represents the number of protons in the nucleus of an atom of that element. Hydrogen has an atomic number of 1, indicating that it has only one proton in its nucleus. This makes hydrogen the simplest and lightest element on the periodic table.
28.
How many neutrons does Be have?
Correct Answer
B. 5
Explanation
Beryllium (Be) is an element with atomic number 4, which means it has 4 protons in its nucleus. The number of neutrons in an atom can be calculated by subtracting the atomic number from the atomic mass. Since the atomic mass of beryllium is approximately 9, subtracting 4 from 9 gives us 5 neutrons. Therefore, the correct answer is 5.
29.
A subatomic particle with no charge is:
Correct Answer
C. Neutron
Explanation
A subatomic particle with no charge is a neutron. Unlike protons and electrons, which carry positive and negative charges respectively, neutrons have no charge. Neutrons are found in the nucleus of an atom along with protons, and they help to stabilize the nucleus by balancing the positive charges of the protons.
30.
The number of protons in an atom is known as the?
Correct Answer
B. Atomic number
Explanation
The atomic number of an atom represents the number of protons it contains. Protons are positively charged particles found in the nucleus of an atom. The atomic number is a fundamental property of an element and determines its position in the periodic table. It also determines the number of electrons in a neutral atom since atoms are electrically neutral and have the same number of protons and electrons. Therefore, the correct answer is atomic number.
31.
The element chlorine has an electron configuration of 2,8,7. It is in which group and period?
Correct Answer
B. Group 17 and period 3
Explanation
The element chlorine has an electron configuration of 2,8,7, meaning it has 17 electrons in total. The group number corresponds to the number of valence electrons, which is the number of electrons in the outermost energy level. Since chlorine has 7 valence electrons, it belongs to group 17. The period number corresponds to the number of energy levels or shells in an atom. Chlorine has 3 energy levels, so it is in period 3. Therefore, the correct answer is group 17 and period 3.