Amy, two months pregnant, wonders how the embryo is being fed and what parts of the body have formed. “I don’t look pregnant yet, so does that mean not much development has taken place?” she asks. How would you respond to Amy?
> Nine-year-old Jasmine thinks she isn’t good at sports, and she doesn’t like physical education class. Suggest strategies her teacher can use to improve her pleasure and involvement in physical activity.
> Alice and Wayne want their two young children to become morally mature, caring individuals. List some parenting practices they should use and some they should avoid.
> Lena wonders why her 4-year-old son Gregor’s teacher provides extensive playtime in learning centres during each preschool day. Explain to Lena how adult-supported play can promote literacy and math skills essential for academic success.
> Mabel and Chad want to do everything they can to support their 3-year-old daughter’s motor development. What advice would you give them?
> What attachment pattern did Timmy display when Vanessa picked him up from child care, and what factors probably contributed to it?
> Cite ways that parenting contributes to pre-schoolers’ self-concept, self-esteem, emotional understanding, emotional self-regulation, self-conscious emotions, and empathy and sympathy. Do you see any patterns? Explain.
> Fifteen-month-old Joey’s developmental quotient (DQ) is 115. His mother wants to know exactly what this means and what she should do to support his intellectual development. How would you respond?
> Nine-month-old Byron has a toy with large, coloured push buttons on it. Each time he pushes a button, he hears a nursery tune. Which learning capacity is the manufacturer of this toy taking advantage of? What can Byron’s play with the toy reveal about hi
> Cecilia and Anna each gave birth to a 3-pound baby seven weeks preterm. Cecilia is single and on welfare. Anna and her husband are happily married and earn a good income. Plan an intervention appropriate for helping each baby develop.
> Nora, pregnant for the first time, believes that a few cigarettes and a glass of wine a day won’t be harmful. Provide Nora with research-based reasons for not smoking or drinking.
> Check your local newspaper or one or two national news websites to see how often articles appear on the condition of children and families. Why is it important for researchers to communicate with the public about children’s needs?
> What aspect of behaviourism made it attractive to critics of psychoanalytic theory? How did Piaget’s theory respond to a major limitation of behaviourism?
> Cite examples of how older children’s capacity to take more information into account enhances their emotional understanding, perspective taking, and moral understanding.
> Explain why gains in executive function are vital for mastery of reading and math in middle childhood.
> Select one of the following health problems of middle childhood: obesity, myopia, bedwetting, asthma, or unintentional injuries. Explain how both genetic and environmental factors contribute to it.
> How does emotional self-regulation affect the development of empathy and sympathy? Why are these emotional capacities vital for positive peer relations?
> Select two of the following features of preoperational thought: egocentrism, a focus on perceptual appearances, difficulty reasoning about transformations, and lack of hierarchical classification. Present evidence indicating that pre-schoolers are more c
> Explain how Piaget’s and Vygotsky’s theories complement each other. How would classroom practices inspired by these theories be similar? How would they differ?
> Using research on malnutrition or unintentional injuries, show how physical growth and health in early childhood result from a continuous, complex interplay between heredity and environment.
> Explain how findings on ethnic and gender differences in temperament illustrate gene–environment correlation.
> List techniques that parents can use to scaffold development of categorization in infancy and toddlerhood, and explain why each is effective.
> Explain why breastfeeding can have lifelong, favourable consequences for the development of infants in poverty-stricken regions of the world.
> How might natural childbirth positively affect the parent–new-born relationship? Explain how your answer illustrates bidirectional influences between parent and child, emphasized in ecological systems theory.
> How is brain development related to fatal capacities and behaviour? What implications do individual differences in fatal behaviour have for infant temperament after birth?
> Why is genetic counselling called a communication process? Who should seek it, and why?
> A 4-year-old becomes frightened of the dark and refuses to go to sleep at night. How would a psychoanalyst and a behaviourist differ in their views of how this problem developed?
> Ten-year-old Marla says her classmate Bernadette will never get good grades because she’s lazy. Jane believes that Bernadette tries but can’t concentrate because her parents are divorcing. Why is Marla more likely than Jane to develop prejudices?
> What aspects of brain development support the tremendous gains in language, thinking, and motor control of early childhood?
> Lizzie knows that if you have difficulty learning part of a task, you should devote extra attention to that part. But she plays each of her piano pieces from beginning to end instead of practicing the hard parts. Explain why Lizzie does not engage in cog
> Nine-year-old Talia is afraid to hug and kiss her grandmother, who has cancer. What might explain Talia’s mistaken belief that the same behaviours that cause colds to spread might lead her to catch cancer? What would you do to change her thinking?
> Three-year-old Ben lives in the country, with no other pre-schoolers nearby. His parents wonder whether it is worth driving Ben into town once a week to participate in a peer play group. What advice would you give Ben’s parents, and why?
> Tanisha sees her 5-year-old son Toby talking aloud to himself as he plays. She wonders whether she should discourage this behaviour. Use Vygotsky’s theory to explain why Toby talks to himself. How would you advise Tanisha?
> One day, Leslie prepared a new snack to serve at preschool: celery stuffed with ricotta cheese and pineapple. The first time she served it, few children touched it. How can Leslie encourage the children to accept the snack? What tactics should she avoid?
> Mandy and Jeff are parents of 2-year-old inhibited Sam and 3-year-old irritable Maria. Explain the importance of effortful control to Mandy and Jeff, and suggest ways they can strengthen it in each of their children.
> When Timmy was 18 months old, his mother stood behind him, helping him throw a large ball into a box. As his skill improved, she stepped back, letting him try on his own. Using Vygotsky’s ideas, explain how Timmy’s mother is supporting his cognitive deve
> Eight-month-old Shaun is well below average in height and painfully thin. What serious dietary disease does he likely have, and what types of intervention, in addition to dietary enrichment, can help restore his development?
> Which of the capacities listed in Table 6.2 indicate that mental representation emerges earlier than Piaget concluded? Data from Table 6.2:
> Explain how either too little or too much stimulation can impair cognitive and emotional development in the early years.
> Sharon, a heavy smoker, has just arrived at the hospital in labour. Which one of the medical interventions discussed in the preceding sections is her doctor justified in using?
> Contrast the positive impact of the baby’s production of high levels of stress hormones during childbirth with the negative impact of severe maternal stress on the fetus?
> Why is it incorrect for couples who postpone childbearing until age 35 or later to conclude that medical advances can overcome fertility problems?
> Explain why parents of children with genetic disorders often experience increased stress. What factors, within and beyond the family, can help these parents support their children’s development?
> Review Reiko’s story in the introduction to this chapter. What factors likely contributed to her resilience in the face of wartime persecution, relocation, and internment?
> Should parents try to promote children’s self-esteem by telling them they’re “smart” or “wonderful”? Explain.
> Nine-year-old Adrienne spends many hours helping her father build furniture in his woodworking shop. How might this experience facilitate Adrienne’s advanced performance on Piagetian seriation problems?
> Joey complained to his mother that it wasn’t fair that his younger sister Lizzie was almost as tall as he was. He worried that he wasn’t growing fast enough. How should Rena respond to Joey’s concern?
> On a hike with his family, 5-year-old Ryan became frightened when he reached a steep section of the trail. His father gently helped him climb up while saying, “Can you be brave? Being brave is when you feel scared but you do it anyway.” What aspect of em
> Three-year-old Will understands that his tricycle isn’t alive and can’t feel or move on its own. But at the beach, while watching the sun dip below the horizon, will exclaimed, “The sun is tired. It’s going to sleep!” What explains this apparent contradi
> Dental check-ups revealed a high incidence of untreated tooth decay in a U.S. preschool program serving low-income children. Using findings presented in this and previous chapters, list possible contributing factors.
> Why do children of depressed parents have difficulty regulating emotion? What implications do their weak self-regulatory skills have for their response to cognitive and social challenges?
> Two protons approach each other with 70.4 MeV of kinetic energy and engage in a reaction in which a proton and a positive pion emerge at rest. What third particle, obviously uncharged and therefore difficult to detect, must have been created?
> Fill in the missing particle. Assume that (a) occurs via the strong interaction while (b) and (c) involve the weak interaction. (a) (b) (c)
> Occasionally, high - energy muons collide with electrons and produce two neutrinos according to the reaction μ+ + e- ( 2v. What kind of neutrinos are they?
> Find the energy released in the fission reaction n + 23592U ( 4098Zr + 13552Te + 3n The atomic masses of the fission products are 97.9120 u for 4098Zr and 134.9087 u for 13552Te.
> Find the energy released in the fusion reaction 11H + 23He ( 24He + e+ + v
> Name at least one conservation law that prevents each of the following reactions from occurring. (a) (b) (c)
> A ∑0 particle traveling through matter strikes a proton. A ∑+, a gamma ray, as well as a third particle, emerge. Use the quark model of each to determine the identity of the third particle.
> What is the electrical charge of the baryons with the quark compositions (a) ūūd- and (b) ūd-d-? What are these baryons called?
> Identify the particles corresponding to the quark states (a) suu, (b) ūd, (c) s-d, and (d) ssd.
> The quark compositions of the K0 and Λ0 particles are ds- and uds, respectively. Show that the charge, baryon number, and strangeness of these particles equal the sums of these numbers for their quark constituents.
> In the theory of quantum chromodynamics, quarks come in three colors. How would you justify the statement, “All baryons and mesons are colorless”?
> Find the number of electrons, and of each species of quark, in 1.00 L of water.
> The quark composition of the proton is uud, whereas that of the neutron is udd. Show that the charge, baryon number, and strangeness of these particles equal the sums of these numbers for their quark constituents.
> Determine whether or not strangeness is conserved in the following decays and reactions. (a) Λ0 ( p + π- (b) π- + p ( Λ0 + K0 (c) (d) (e) (f)
> (a) Show that baryon number and charge are conserved in the following reactions of a pion with a proton: (b) The first reaction is observed, but the second never occurs. Explain these observations. (c) Could the second reaction happen if it created a th
> If the average energy released in a fission event is 208 MeV, find the total number of fission events required to operate a 100. - W light-bulb for 1.0 h.
> Which of the following processes are allowed by the strong interaction, the electromagnetic interaction, the weak interaction, or no interaction at all? (a) (b) (c) (d) (e)
> Determine which of the reactions below can occur. For those that cannot occur, determine the conservation law (or laws) that each violates. (a) (b) (c) (d) (e)
> Each of the following reactions is forbidden. Determine a conservation law that is violated for each reaction. (a) (b) (c) (d) (e)
> For the following two reactions, the first may occur but the second cannot. Explain. K0 ( π+ + π- (can occur) Λ0 ( π+ + π- (cannot occur)
> (a) Determine the muon - lepton number in the reaction μ- ( e- + v-e + vμ. (b) Determine the value of strangeness in the reaction π- + p ( Λ0 + K0.
> A radioactive sample has an activity R. For each of the following changes, indicate whether the activity would increase, decrease, or remain unchanged. Indicate your answers with I, D, or U. (a) The number of radioactive nuclei in the sample is doubled.
> (a) Determine the baryon number of the reaction p + p- ( 2(. Determine (b) The baryon number and (c) The electron - lepton number of the reaction Ω- ( Λ0 + K-.
> A neutral pion at rest decays into two photons according to π0 ( ( + ( Find the energy, momentum, and frequency of each photon.
> A photon with an energy of 2.09 GeV creates a proton – antiproton pair in which the proton has a kinetic energy of 95.0 MeV. What is the kinetic energy of the antiproton?
> A photon produces a proton – antiproton pair according to the reaction ( ( p + p-. What is the minimum possible frequency of the photon? What is its wavelength?
> A reaction that has been considered as a source of energy is the absorption of a proton by a boron - 11 nucleus to produce three alpha particles: 11H + 115B ( 3(24He) This reaction is an attractive possibility because boron is easily obtained from Earth’
> A typical uranium - 234 fission event releases 208 MeV of energy. Determine (a) The energy released per event in joules and (b) The change in mass during the event.
> Assume a deuteron and a triton are at rest when they fuse according to the reaction 12H + 13H ( 24He + 01n + 17.6 MeV Neglecting relativistic corrections, determine the kinetic energy acquired by the neutron.
> Another series of nuclear reactions that can produce energy in the interior of stars is the cycle described below. This cycle is most efficient when the central temperature in a star is above 1.6 x 107 K. Because the temperature at the center of the Sun
> Find the energy released in the fusion reaction 12H + 12H ( 13H + 11H
> Find the energy released in the fusion reaction 11H + 12H ( 23He + (
> Particles known as resonances have very short half - lives, on the order of 10-23s. Would you guess that they are hadrons or leptons? Explain.
> When a star has exhausted its hydrogen fuel, it may fuse other nuclear fuels. At temperatures above 1.0 x 108 K, helium fusion can occur. Write the equations for the following processes. (a) Two alpha particles fuse to produce a nucleus A and a gamma ray
> The proton – proton cycle responsible for the Sun’s 3.84 x 1026 W power output yields about 26.7 MeV of energy for every four protons that are fused into a helium nucleus. Determine (a) The energy in joules released during each proton – proton cycle fusi
> Suppose a deuterium – deuterium fusion reactor is designed to have a plasma confinement time of 1.50 s. Determine the minimum ion density per cubic cm required to obtain a net power output from the reactor.
> Seawater contains 3 mg of uranium per cubic meter. (a) Given that the average ocean depth is about 4 km and water covers two - thirds of Earth’s surface, estimate the amount of uranium dissolved in the ocean. (b) Estimate how long this uranium could supp
> An all - electric home uses approximately 2.00 x 103 kWh of electric energy per month. How much uranium - 235 would be required to provide this house with its energy needs for one year? Assume 100% conversion efficiency and 208 MeV released per fission.
> According to one estimate, there are 4.4 x 106 metric tons of world uranium reserves extractable at $130/kg or less. About 0.70% of naturally occurring uranium is the fissionable isotope 235U. (a) Calculate the mass of 235U in this reserve in grams. (b)
> Natural uranium ore contains about 0.720% of the fissile uranium - 235 isotope. Suppose a sample of uranium ore contains 2.50 x 1028 uranium nuclei. Determine the number of uranium - 235 nuclei in the sample.
> A piece of charcoal used for cooking is found at the remains of an ancient campsite. A 1.00-kg sample of carbon from the wood has an activity equal to 5.00 x 102 decays per minute. Find the age of the charcoal. Hint: Living material has an activity equal
> After how many half-lives will (a) 10.0%, (b) 5.00%, and (c) 1.00% of a radioactive sample remain?
> A by-product of some fission reactors is the isotope 23994Pu, which is an alpha emitter with a half-life of 24000 years: Consider a sample of 1.0 kg of pure 23994Pu at t = 0. Calculate (a) The number of 23994Pu nuclei present at t = 0 and (b) The initia
> Explain the main differences between alpha, beta, and gamma rays.
> The theory of nuclear astrophysics is that all the heavy elements like uranium are formed in the interior of massive stars. These stars eventually explode, releasing the elements into space. If we assume that at the time of explosion there were equal amo
> After the sudden release of radioactivity from the Chernobyl nuclear reactor accident in 1986, the radioactivity of milk in Poland rose to 2.00 x 103 Bq/L due to iodine - 131, with a half - life of 8.04 days. Radioactive iodine is particularly hazardous
> A medical laboratory stock solution is prepared with an initial activity due to 24Na of 2.5 mCi/mL, and 10.0 mL of the stock solution is diluted at t0 = 0 to a working solution whose total volume is 250 mL. After 48 h, a 5.0 - mL sample of the working so
> Many radioisotopes have important industrial, medical, and research applications. One of these is 60Co, which has a half - life of 5.2 years and decays by the emission of a beta particle (energy 0.31 MeV) and two gamma photons (energies 1.17 MeV and 1.33
> In a piece of rock from the Moon, the 87Rb content is assayed to be 1.82 x 1010 atoms per gram of material and the 87Sr content is found to be 1.07 x 109 atoms per gram. (The relevant decay is 87Rb ( 87Sr + e-. The half - life of the decay is 4.8 x 1010
> The 14C isotope undergoes beta decay according to the process given by Equation 29.15. Find the Q value for this process. Equation 29.15:
