BTEC APPLIED SCIENCE UNIT 1 EXAM WITH QUESTIONS AND CORRECT ANSWERS 2025 A+ PASS!!! Explain why root hair cells have an elongated section known as the root hair - correct answersIncreased surface area for maximum movement of water into the cell Explai

BTEC APPLIED SCIENCE UNIT 1 EXAM WITH QUESTIONS AND CORRECT ANSWERS 2025 A+ PASS!!! Explain why root hair cells have an elongated section known as the root hair - correct answersIncreased surface area for maximum movement of water into the cell Explain why root hair cells have a large vacuole - correct answers-Contains cell sap with low water potential to encourage water into the cell Explain why root hair cells have thin cellulose walls - correct answers-Encourage movement of water and minerals into the cell Describe the adaptations of a sperm cell - correct answers-Undulipodium Lots of mitochondria Shaped head containing acrosome Haploid nucleus Explain why a sperm cell has an undulipodium - correct answers-To allow the sperm to move to the egg Explain why sperm cells contain large numbers of mitochondria - correct answers-To produce the large amounts of energy needed for movement Explain why sperm cells have a shaped head - correct answers-To push through the protective layer of the egg cell Explain why sperm cells contain acrosome in the head - correct answers-To digest the zona pellucida to allow entry into the egg cell Explain why sperm cells have a haploid nucleus - correct answers-Contains half the genetic material. How many electrons can an s subshell hold? - correct answers-2 How many electrons can a p subshell hold? - correct answers-6 How many electrons can a d subshell hold? - correct answers-10 Which subshells are available in the first energy level? - correct answers-s Which subshells are available in the second energy level? - correct answers-s and p Which subshells are available in the third energy level? - correct answers-s, p and d What is Hund's rule? (Think bus seats!) - correct answers-Orbitals must all be singly filled before they can be doubly occupied Which elements do not fill the 4s subshell before the 3d subshell? - correct answers-Copper and chromium Define the term ionic bond - correct answers-The electrostatic attraction between oppositely charged ions What is the charge of an ion from group 1? - correct answers-+1 What is the charge of an ion from group 2? - correct answers-+2 What is the charge of an ion from group 6? - correct answers--2 What is the charge of an ion from group 7? - correct answers--1 Explain how atoms of sodium react with atoms of chlorine - correct answers-Na loses its 2s1 electron gaining a +ve charge. Cl gains an electron in the 3p subshell gaining a -ve charge. The opposite charges attract to form NaCl Why do ionic bonds have such high melting points? - correct answers-Each +ve ion is surrounded by 6 -ve ions and vice versa. Strong electrostatic attraction in every direction. Requires a large amount of energy to break State two factors that affect the strength of an ionic bond - correct answers-Size of ion and charge on ion When can ionic substances conduct electricity? - correct answers-When molten or in aqueous solution Describe the properties of ionic compounds - correct answers-Conduct electricity when molten or aqueous solution High melting/boiling points Usually soluble in water Define the term covalent bond - correct answers-A shared pair of electrons Which metals lose electrons from the 4s subshell before the 3d subshell? - correct answersTransition metals Why do metals have such high melting points? - correct answers-Strong force of attraction between positive ions and delocalised electrons. This requires a large amount of energy to overcome. State the two factors that affect the strength of metallic bonding - correct answers-Size of ion Charge on ion Explain how the charge on metal ions affects the strength of the metallic bond - correct answers-The larger the +ve charge the greater the attraction between the nucleus and the delocalised electrons Explain how the size of the metal ions affects the strength of the metallic bond - correct answers-The smaller the +ve ion the closer the nucleus is to the delocalised electrons creating a greater attraction Explain why metals conduct electricity - correct answers-The delocalised electrons 'carry' charge. Current flows because of this. Explain why metals conduct heat - correct answers-Particles are paced tightly so kinetic energy is passed from ion to ion. The delocalised electrons also enable heat to be passed. Explain why metals are ductile and malleable - correct answers-The lattice structure allows layers of metal ions to slide over each other without disrupting bonding Name the 3 forces between molecules - correct answers-Van der Waals Permanent dipole-dipole Hydrogen bonds