CHEM - ELEMENTS AND COMPOUNDS Flashcards
(17 cards)
What is the main distinction between metals and non-metals?
Metals are typically shiny, conductive, malleable, and ductile, while non-metals are usually dull, insulative, brittle, and not malleable.
How are the physical properties of metals and non-metals related to their uses?
Metals are used in electrical wiring and construction due to their conductivity and strength, while non-metals are used in insulation and chemical applications due to their reactivity and insulating properties.
What is the significance of technological advancements in our understanding of elements?
Our understanding of elements has evolved with technology, leading to the discovery of new elements and the development of the periodic table.
Define the term ‘atom’.
An atom is the smallest unit of matter that retains the properties of an element.
What are protons, neutrons, and electrons?
- Protons: positively charged particles in the nucleus
- Neutrons: neutrally charged particles in the nucleus
- Electrons: negatively charged particles orbiting the nucleus
Describe the structure of an atom.
An atom consists of a nucleus containing protons and neutrons, surrounded by electrons in orbitals.
Define a compound.
A compound is a combination of two or more elements chemically bonded together.
What is an element?
An element is a pure substance that cannot be broken down into simpler substances by chemical means.
List some common examples of compounds.
- Water
- Hydrogen chloride (hydrochloric acid)
- Carbon dioxide
- Methane
- Ammonia
Use diagrammatic representations and physical models to represent _______.
water and methane.
What is the difference between compounds and elements?
Compounds consist of two or more different types of atoms bonded together, while elements consist of only one type of atom.
Recall the difference between mixtures and pure substances.
Mixtures are combinations of two or more substances that retain their individual properties, while pure substances have a uniform composition.
Distinguish between elements, compounds, and mixtures in terms of the relationships between particles.
- Elements: consist of identical particles
- Compounds: consist of different particles chemically bonded
- Mixtures: consist of different particles that are physically mixed
What are controlled, independent, and dependent variables?
- Controlled variable: kept constant
- Independent variable: manipulated by the researcher
- Dependent variable: measured outcome
How do you design a fair test?
A fair test is designed by controlling variables to ensure that only the independent variable affects the dependent variable.
What does the term validity mean?
Validity refers to the extent to which a test or investigation measures what it is supposed to measure.
How can you assess the validity of an investigation?
Assess the validity by examining the reliability of the methods, the control of variables, and the relevance of the data collected.
