Химия для вступительных экзаменов на сестринские программы: лист заданий с ответами

What is a beta particle?

1. AA helium nucleus with two protons and two neutrons
2. BA neutron that leaves the nucleus
3. CA high-energy electron released from a nucleus
4. DA wave of visible light

What are the building blocks of carbohydrates such as starch?

1. AFatty acids joined to a glycerol molecule
2. BNucleotides
3. CMonosaccharides (simple sugars) such as glucose
4. DAmino acids

What is absolute zero?

1. A0 °F, the temperature of a salt and ice mixture
2. B0 °C, the point at which pure water freezes into ice
3. C−100 °C, the coldest temperature on Earth
4. D0 K, about −273 °C, the lowest possible temperature

Oxygen has 8 electrons. What is its electron configuration?

1. A1s² 2p⁶
2. B1s² 2s² 2p⁶
3. C1s² 2s² 2p⁴
4. D1s² 2s⁶

In a closed container, 10 g of substance A reacts completely with 5 g of substance B. What is the total mass of the products?

1. A50 g
2. B15 g
3. C10 g
4. D5 g

Which of these is a colloid?

1. APure water
2. BMilk
3. CSand in water
4. DSalt water

Why is it easier to remove the outer electron from a potassium atom than from a lithium atom?

1. APotassium's outer electron is farther from the nucleus and more shielded by inner electrons
2. BPotassium's outer electron is in a full shell
3. CLithium has more electron shells than potassium
4. DPotassium has fewer protons, so its nucleus pulls much more weakly on every electron

Carbon-12 and carbon-14 react in exactly the same way in chemical reactions. Why?

1. AThey have the same mass number
2. BCarbon-14 turns into carbon-12 before reacting
3. CThey have the same number of protons and electrons
4. DThey have the same number of neutrons