Elements and Substances

Question 1:Diagram 1.1 shows an experiment conducted in a science laboratory.Diagram 1.1(a) Name the process occurs in the conical flask in Diagram 1.1.(b) Mark ( √ ) gas W released from the process in 1(a).Diagram 1.2 shows distillation process of mixture K. Mixture K is the product in the conical flask from Diagram 1.1.Diagram 1.2(c) … Read more

Question 1:Diagram 1.1 and Diagram 1.2 show an experiment to study the heat conductivity between metal and non-metal.Table shows the time taken for the thumb-tack to fall after both rods are heated.(a) State one hypothesis for this experiment. [1 mark](b) State the variables in this experiment.   (i) Constant variable [1 mark]   (ii) Manipulated variable … Read more

Question 1:Diagram 1.1 and Diagram 1.2 show an experiment to study the electrical conductivity of lead(II) bromide.(a)(i) Based on Diagram 1.2, what is your observation on the needle of the ammeter? [1 mark] (ii) What is the reading of the ammeter in Diagram 1.2? [1 mark](b) State the variables I this experiment.   (i) Manipulated … Read more

Question 1:Diagram 1.1 shows the structure of an atom.(a) P and Q are subatomic particles.   Name P and Q. [2 marks](b) What is the charge of P? [1 mark](c) What is the nucleon number of this atom? [1 mark](d) Diagram 1.2 shows the structure of three atoms.(i) Which atoms are isotopes? [1 mark]  Mark … Read more

Question 1:Diagram below shows the changes in the state of matter of a substance.Based on the Diagram,(a) name the processes R, S and T using the following information. [3 marks](b) What happens to the kinetic energy of the particles in the substance during process R? [1 mark](c) What happens to the movement of the particles … Read more

4.5.2 Classification of Substances 1. Types of substances:   2. The physical properties of substances depend on (a)  types of particles they contain,    (b)  arrangement of the particles,    (c)  forces of attraction between the particles. Substances made of atoms (or Atomic substances) 1.   Atomic substances are substances that consist of only atoms. 2. … Read more

4.5 Properties of Substances Based on their Particle Content 1.   Matter is anything that occupies space and has mass. 2.   Matter can be divided into elements and compounds. 4.5.1 Atoms, Molecules and Ions 1.   Substances are made of tiny particles called atoms, molecules and ions. 2.   Atoms are the tiniest particles in an element. 3.  … Read more

4.4 Classification of Elements in the Period Table 4.4.1 The classification of Elements 1. In modern periodic table, the elements are arranged in ascending order of proton number. Group 1. The vertical columns of the periodic table is called group. 2. There are 18 groups in the periodic table. 3. Elements in the same group have similar chemical properties. … Read more

4.3.2 Isotopes 1. Isotopes are atoms of certain elements which have the same number of protons but different number of neutrons in the nucleus of the atoms. 2. Isotopes of the same element have same chemical properties. For example, both carbon-12 and carbon-13 burn in oxygen to form carbon dioxide.   3. Physical properties of isotopes are different. … Read more

4.3 Proton Number and Nucleon Number in Atoms of Elements 4.3.1 Proton Number and Nucleon Number 1. The proton number represents the number of proton found in nucleus of an atom. Sometime, it is also known as the atomic number.   2. Nucleons are the subatomic particles inside the nucleus of an atom, Nucleon = protons and … Read more