Yr10 summer hw Flashcards
order these of increasing size : organ, tissue, cell, system
cell, tissue, organ, system
what is an emzyme?
a protein molecule that acts as a biological catalyst
which emzyme breaks down starch?
amylase
what small molecule are proteins made of?
amino acids
what is the test for sugars?
add benedicts reagent and heat
what is meant by an emzyme being “denatured”?
active site has changed shape so substrate no longer fits
which scientist conducted the gold leaf experiment to determine the nuclear model of an atom?
Rutherford
what is an isotope?
an atom of an element with a different number of neutrons
what does atomic number tell you about an atom?
the number of protons (and electrons)
what does atomic mass tell you about an atom?
the number of protons plus the number of neutrons
what is emitted from the nucleus in alpha decay?
2 protons and 2 neutrons (alpha particle)
what material can absorb radiation?
aluminium
which type of radiation is the most ionizing?
alpha
what is the formula of a hydroxide ion?
OH-
what is the name given to an atom or ion gaining electrons?
reduction
what is a displacement reaction?
a more reactive metal takes the place of a less reactive metal in a compound
what salts are produced when hydrochloric acid reacts with a substance?
chlorides
draw the circuit symbol for an ammeter
—-(A)—-
draw the circuit symbol for an LED
^^
//
— >|—
state the equation the links current, potential difference, and resistance
PD=current x resistance
what happens to current in a series circuit?
it is the same through each componemt
what happens to current on a parallel circuit?
the total current in the circuit is the sum of the currents through each branch
what is the name given to a chemical reaction that takes in thermal energy from the surroundings?
endothermic
what is meant by activation energy?
the minimum energy required for a reaction to take place
how is the temp change calculated?
max / min temp - initial temp
the number of protons and neutrons in the beryllium atom?
P = 4 N=5
what is the relative charge on a beryllium ion?
+2
what state of matter is shown in box C F3?
gas
what is the process when state B(liquid) changes into A(solid)?
freezing
how can state B be changed into C?
heat/evaporate/boil
who was the existence of the neutron discovered by?
chadwick
suggest a limitation of using a ball and stick model for a water molecule
not to scale, not 3D, incorrect arrangement in space, electrons/shells not shown
ice has a low melting point because the intermolecular forces are _____.
weak
(1 oxygen, 4 hydrogen, 1 carbon) shown in the image
what is the molecular formula?
CH40
what is the number of bonds formed by each carbon atom in diamond?
4
give 2 physical properties of diamond
very hard, very high melting point, does not conduct electricity
name 2 other substances with giant covalent structures
graphite, silicon dioxide
